docs: mark connection badge field-verified (2-machine call 2026-07-08)

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
network: per-peer connection badge (direct/relay, RTT, loss, bitrate)
2026-07-08 17:07:54 -04:00 · 2026-07-08 15:15:22 -04:00 · 2026-07-06 17:20:00 -04:00 · 2026-07-06 16:47:06 -04:00 · 2026-07-06 13:22:31 -04:00 · 2026-07-06 13:09:22 -04:00
88 changed files with 15547 additions and 1999 deletions
@@ -0,0 +1,42 @@
+name: CI
+
+# Runs on the self-hosted host-mode runner on the desktop (label `arch`). The
+# gitbutter VPS only queues the job; all compile/test compute happens locally.
+on:
+  push:
+    branches: [main]
+  pull_request:
+  workflow_dispatch:
+
+jobs:
+  check:
+    runs-on: arch
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Toolchain versions
+        run: |
+          rustc --version
+          cargo --version
+          cargo clippy --version
+          cargo deny --version
+          cargo audit --version
+
+      - name: Format check
+        run: cargo fmt --all -- --check
+
+      - name: Clippy (all targets, warnings as errors)
+        run: cargo clippy --all-targets -- -D warnings
+
+      - name: Tests
+        run: cargo test --all-targets
+
+      - name: Doc tests
+        run: cargo test --doc
+
+      - name: cargo-deny (advisories, bans, licenses, sources)
+        run: cargo deny check
+
+      - name: cargo-audit
+        run: cargo audit
@@ -0,0 +1,73 @@
+# Changelog
+
+All notable changes to PeerSpeak are documented here.
+
+## [0.6.3] — 2026-07-06
+
+### Added
+- **In-app screen-sharing controls.** A new **Screen sharing** section in Settings, plus a per-call **quality picker** on the Share control, put the whole share pipeline under your control without editing config files. Encode side: quality preset, bitrate, framerate, maximum resolution, maximum viewers, a force-software-encode switch, and an escape hatch for extra pixelpass arguments. Playback side: choose **mpv or VLC**, toggle **hardware decoding**, pick a buffering posture (low-latency vs. smooth), set the demuxer cache, and pass extra mpv arguments. Everything is stored locally in your config and defaults are unchanged, so existing setups keep working as-is.
+
+### Fixed
+- **Shared video no longer freezes on the first frame while audio keeps playing.** Hardware decoding now defaults **off**; forcing `--hwdec=auto` stalled some viewers' hardware decoder on frame 1. You can re-enable hardware decoding from the new Screen sharing settings if your machine handles it well.
+- **The per-call quality picker is now honored.** The inline quality dropdown next to the Share button was being reset to the saved default before a share started, so every share silently used the default quality regardless of what you picked.
+- **VLC now respects your playback settings.** VLC hardware-decodes by default, so a VLC viewer previously ignored the hardware-decode toggle (and could hit the same frame-1 freeze) and the buffering posture. VLC viewers now map both settings onto VLC's own options.
+
+[0.6.3]: https://gitbutter.xyz/mollusk/peerspeak/releases/tag/v0.6.3
+
+## [0.6.2] — 2026-07-03
+
+### Fixed
+- **Friends list now reflects status changes without a restart.** A presence probe that fails now actively marks the friend **offline**, so a friend who goes offline, leaves a room, or turns invisible no longer lingers showing a stale "online" / "in a room" status until PeerSpeak is relaunched. Previously only successful probes updated the list, so it could ratchet a friend's status up but never down. The auto-refresh interval was also shortened from 60s to **15s** so the list tracks changes more closely.
+
+### Added
+- **Manual "⟳ Rescan" button** on the Friends panel that refreshes everyone's presence immediately, instead of waiting for the next auto-refresh.
+
+### Licensing
+- **PeerSpeak is now released under the MIT License** (previously an unlicensed private build). Added a `LICENSE` file and a `THIRD_PARTY_LICENSES` file enumerating the full dependency manifest plus the canonical text of every referenced license, with notices for the statically bundled Opus codec and the embedded fonts (Iced-Icons, Cantarell/OFL-1.1). Both files ship in the Arch and Debian packages.
+
+[0.6.2]: https://gitbutter.xyz/mollusk/peerspeak/releases/tag/v0.6.2
+
+## [0.6.0] — 2026-06-28
+
+### Added
+- **Shared music listening (W22).** A new **Playlist** panel lets you build a personal queue of local audio files and play them on a dedicated music player — Browse to add tracks, play/pause, previous/next, seek, per-track reorder, remove, and a local volume slider, all persisted across sessions. `.pls` and `.m3u` playlists can be imported (remote and non-audio entries are skipped).
+- **Tune in to a friend's music.** Flip **"Let others tune in"** and peers see your current track under the **Public** tab; one click on **Listen** streams it to them. Playback is **timeline-synced** — play, pause, skip, and seek mirror across everyone with no drift — and the next track is **prefetched for gapless** transitions. Each listener gets an independent **per-source volume**, so music sits under voice at whatever level they like; voice chat stays fully audible throughout.
+- **Standalone Playlist card in the 3-Column layout.** The playlist now lives in its own card stacked under the chat, with a draggable divider to resize it and its own scrollbar when space is tight. The other layouts keep the playlist in the Controls panel.
+
+### Security
+- Shared-music metadata is treated as untrusted: the broadcast track name is sanitized and its size is cap-checked at gossip ingest, fetched bytes are confirmed to be audio before decoding, and only a small descriptor ever rides gossip — track bytes move point-to-point over the existing files plane, one fetch in flight at a time.
+
+### Changed
+- **Wire protocol bump (gossip v5).** Shared listening adds presence fields, so **0.6.0 peers cannot share a swarm with 0.5.x peers** — everyone in a room must update together.
+
+[0.6.0]: https://gitbutter.xyz/mollusk/peerspeak/releases/tag/v0.6.0
+
+## [0.5.1] — 2026-06-27
+
+### Added
+- **Volume control for inline chat audio clips.** A master volume slider plus a **Universal volume** toggle now sit in the Chat panel header, and every audio attachment gets its own 🔊 slider on its play row. With Universal volume on (the default), one level applies to all clips and persists across sessions; turn it off to give each clip its own independent level.
+
+## [0.5.0] — 2026-06-27
+
+### Added
+- **Right-click context menu** (Cut / Copy / Paste / Select All) on every text-entry field. (A9)
+- **Selectable, copyable text** for values that used to be read-only: your full node ID and the room ticket can now be click-selected and copied, and **chat messages are drag-selectable** (highlight + Ctrl+C / Ctrl+A) while clickable links keep working. (W21 Phase 1 + 2)
+- **Clock-skew warning**: when a peer can't be seen because the two systems' clocks differ by more than the replay-protection window, PeerSpeak now shows a "your clocks are out of sync" banner instead of failing silently. (A25)
+- **Per-application audio capture for screen-share**, removing the call-audio loopback echo when sharing a window, plus surfacing of pixelpass startup errors. (A23)
+
+### Changed / Fixed
+- **Critical commands are now delivered reliably under load** — muting, releasing push-to-talk, and leaving a room can no longer be silently dropped while a slider is being dragged (prevents a hot-mic state mismatch). (A15)
+- Screen-share now passes `--strict-audio` and surfaces app-audio drop warnings; the source picker state machine and pactl handling were hardened. (A23)
+- Per-peer volume control path verified and covered by regression tests. (A24)
+
+### Security
+- Hardened against insider resource-exhaustion: bounded + author-keyed chat attachment cache, capped recovery-identity state, and other Tier-C caps (F-01 / F-02 / F-03 / F-12).
+
+### Packaging
+- Added Debian/Ubuntu `.deb` packaging (cargo-deb metadata); the official `.deb` is now built on **Debian 12 (bookworm)** for wide compatibility.
+- Arch `PKGBUILD` clones over anonymous HTTPS.
+
+[0.5.1]: https://gitbutter.xyz/mollusk/peerspeak/releases/tag/v0.5.1
+[0.5.0]: https://gitbutter.xyz/mollusk/peerspeak/releases/tag/v0.5.0
+
+Earlier releases: see git tags `v0.4.0`, `v0.3.0`, `v0.2.0`.
@@ -200,9 +200,9 @@ checksum = "940b3a0ca603d1eade50a4846a2afffd5ef57a9feac2c0e2ec2e14f9ead76000"

 [[package]]
 name = "anyhow"
-version = "1.0.102"
+version = "1.0.103"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7f202df86484c868dbad7eaa557ef785d5c66295e41b460ef922eca0723b842c"
+checksum = "2a4385e2e34eb35d6b3efe798b9eb88096925d87726c0798709bf56d9ed84af3"

 [[package]]
 name = "arbitrary"
@@ -3682,9 +3682,9 @@ checksum = "6b947ae49db0d222b1dbc6b113ce7248a3fc3a6ca21b696717bfc000ba4484d8"

 [[package]]
 name = "memmap2"
-version = "0.9.10"
+version = "0.9.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "714098028fe011992e1c3962653c96b2d578c4b4bce9036e15ff220319b1e0e3"
+checksum = "d1219ed1b7f229ee7104d281dd01d6802fe28bb6e95d292942c4daacdeb798c0"
 dependencies = [
 "libc",
 ]
@@ -4871,7 +4871,7 @@ checksum = "35fb2e5f958ec131621fdd531e9fc186ed768cbe395337403ae56c17a74c68ec"

 [[package]]
 name = "peerspeak"
-version = "0.4.0"
+version = "0.6.3"
 dependencies = [
 "anyhow",
 "async-trait",
@@ -1,11 +1,42 @@
 [package]
 name = "peerspeak"
-version = "0.4.0"
+version = "0.6.3"
 edition = "2024"
-# Application crate, not a crates.io library — refuse `cargo publish` and let
-# cargo-deny's [licenses.private] skip the missing-license check.
+description = "Decentralized peer-to-peer voice chat (Rust/iroh/PipeWire/Opus/iced)"
+license = "MIT"
+# Application crate, not published to crates.io — refuse `cargo publish`.
 publish = false

+# Debian/Ubuntu packaging (cargo-deb). Mirrors packaging/PKGBUILD: only the main
+# `peerspeak` binary ships (not test_net/specview), plus the desktop entry and the
+# hicolor icon set. Runtime shared-lib deps (libpipewire, libopus, libc, …) are
+# resolved by dpkg-shlibdeps via `depends = "$auto"`. Build inside a Debian/Ubuntu
+# distrobox so the binary links that distro's glibc, then `cargo deb --no-build`.
+[package.metadata.deb]
+maintainer = "mollusk <jitty+lc1iz0dc@protonmail.com>"
+copyright = "2026, mollusk. MIT License."
+section = "net"
+priority = "optional"
+depends = "$auto"
+# pixelpass = in-room screen sharing; mpv = the screen-share viewer (vlc fallback).
+recommends = "pixelpass, mpv"
+extended-description = "Decentralized peer-to-peer voice chat over iroh (QUIC) with PipeWire audio, the Opus codec, and an iced GUI. Full-mesh, no central server."
+assets = [
+    ["target/release/peerspeak", "usr/bin/", "755"],
+    ["packaging/peerspeak.desktop", "usr/share/applications/", "644"],
+    ["assets/icons/peerspeak.svg", "usr/share/icons/hicolor/scalable/apps/peerspeak.svg", "644"],
+    ["assets/icons/peerspeak-16.png", "usr/share/icons/hicolor/16x16/apps/peerspeak.png", "644"],
+    ["assets/icons/peerspeak-24.png", "usr/share/icons/hicolor/24x24/apps/peerspeak.png", "644"],
+    ["assets/icons/peerspeak-32.png", "usr/share/icons/hicolor/32x32/apps/peerspeak.png", "644"],
+    ["assets/icons/peerspeak-48.png", "usr/share/icons/hicolor/48x48/apps/peerspeak.png", "644"],
+    ["assets/icons/peerspeak-64.png", "usr/share/icons/hicolor/64x64/apps/peerspeak.png", "644"],
+    ["assets/icons/peerspeak-128.png", "usr/share/icons/hicolor/128x128/apps/peerspeak.png", "644"],
+    ["assets/icons/peerspeak-256.png", "usr/share/icons/hicolor/256x256/apps/peerspeak.png", "644"],
+    ["assets/icons/peerspeak-512.png", "usr/share/icons/hicolor/512x512/apps/peerspeak.png", "644"],
+    ["LICENSE", "usr/share/doc/peerspeak/", "644"],
+    ["THIRD_PARTY_LICENSES", "usr/share/doc/peerspeak/", "644"],
+]
+
 [lib]
 name = "peerspeak"
 path = "src/lib.rs"
@@ -28,7 +59,7 @@ async-trait = "0.1.89"
 base64 = "0.22.1"
 bytes = "1.11.1"
 dirs = "6.0.0"
-iced = { version = "0.14.0", features = ["canvas", "image", "tokio"] }
+iced = { version = "0.14.0", features = ["advanced", "canvas", "image", "tokio"] }
 # W4 custom avatars: decode/resize an arbitrary user image (png/jpeg only to keep
 # the codec surface small). The matching native file picker (`rfd`) is platform-
 # gated below — its backend differs per OS (xdg-portal on Linux, Win32 on Windows).
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 mollusk
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
@@ -0,0 +1,115 @@
+<h1>
+  <img src="assets/icons/peerspeak.svg" width="48" align="left" alt="PeerSpeak icon">
+  PeerSpeak
+</h1>
+
+Decentralized, peer-to-peer voice chat — full-mesh, NAT-traversing, with **no central server**. Built in Rust on [iroh](https://github.com/n0-computer/iroh) (QUIC), PipeWire audio, the Opus codec, and an [iced](https://github.com/iced-rs/iced) GUI.
+
+Create a room, share the join ticket, and talk. Everyone connects directly to everyone else; relays are only used to punch through NATs when a direct path isn't available.
+
+---
+
+## Screenshots
+
+| Launch screen | In a room |
+|---|---|
+| ![Launch screen](docs/screenshots/launch.jpg) | ![In a room](docs/screenshots/in-room.jpg) |
+
+| Settings |
+|---|
+| ![Settings](docs/screenshots/settings.jpg) |
+
+---
+
+## Features
+
+**Rooms & sessions**
+- Create a room → shareable join ticket; join by pasting a ticket.
+- Full-mesh multi-peer rooms with live presence.
+- Recent-rooms list to hop back into a room someone's still in.
+- Remembered nickname and in-call duration timer.
+
+**Audio**
+- PipeWire capture/playback, selectable input and output devices, per-app gain.
+- Opus codec (48 kHz mono, 20 ms frames) with an adaptive jitter buffer + packet-loss concealment.
+- Noise gate with a draggable threshold on a live mic meter (test your mic off-call too).
+- Mix-bus soft limiter and opt-in echo cancellation (PipeWire WebRTC AEC + noise suppression).
+
+**Voice controls**
+- Self-mute, deafen, and rebindable push-to-talk.
+- Per-peer volume, local mute, and speaking indicators.
+
+**Text chat**
+- In-room text chat over the gossip plane, with clickable links and inline image/audio attachments.
+- Drag-selectable, copyable messages; right-click context menu on all text fields.
+
+**Shared music listening**
+- Build a personal playlist of local audio files with a full transport (play/pause, seek, reorder).
+- Let others tune in: peers stream your current track, timeline-synced and gapless, sitting under voice at their own volume.
+
+**Screen share** (via [pixelpass](https://gitbutter.xyz/mollusk/pixelpass))
+- Share your screen; peers click 👁 Watch to open the stream in mpv (vlc fallback).
+- Live badges on sharing peers; per-app audio capture.
+
+**Recording & notifications**
+- Local call recording (mic + incoming mix → WAV in `~/peerspeak-recordings/`).
+- Desktop notifications and event chimes with per-event custom sound overrides.
+
+**UI & networking**
+- Selectable room layouts (3-Column, Bottom Dock, Drawer) with draggable, persisted dividers.
+- 10 built-in themes (Catppuccin, Dracula, Nord, Tokyo Night, Gruvbox, Solarized…), all WCAG-AA checked.
+- Network mode picker (relay-no-discovery default, full n0, or direct-only); retained-address reconnect.
+- Config, window size/position, and all preferences persisted to `~/.config/peerspeak/`.
+
+See [`docs/FEATURES.md`](docs/FEATURES.md) for the full inventory and field-test status, and [`docs/ARCHITECTURE.md`](docs/ARCHITECTURE.md) for internals.
+
+## Roadmap
+
+- **Contacts & invites** — friends list with invite-notification one-click join (design in [`docs/contacts-plan.md`](docs/contacts-plan.md)).
+- **Spatial audio & per-peer EQ.**
+- **Soundboard** — play short clips into the call mix.
+- **Room persistence / invite links** beyond the raw ticket.
+- **Windows support** — cross-compiles and launches under Wine today; needs a real WASAPI audio pass (see [`docs/WINDOWS.md`](docs/WINDOWS.md)).
+
+## Building
+
+PeerSpeak builds with a stable Rust toolchain (edition 2024). Install the system dependencies below, then:
+
+```sh
+cargo build --release
+./target/release/peerspeak
+```
+
+### System dependencies
+
+**Arch Linux**
+
+```sh
+sudo pacman -S --needed rust pipewire opus pkgconf git
+```
+
+**Debian / Ubuntu**
+
+```sh
+sudo apt install build-essential pkg-config clang libclang-dev \
+  libpipewire-0.3-dev libopus-dev libasound2-dev libxcb1-dev
+```
+
+Plus a Rust toolchain via [rustup](https://rustup.rs/). `clang`/`libclang` are needed for the PipeWire bindings (bindgen).
+
+At runtime you need a running **PipeWire** server. Screen sharing additionally requires `pixelpass` on your `PATH`, and `mpv` (or `vlc`) to watch a peer's share.
+
+### Packaging
+
+- **Arch:** `cd packaging && makepkg -si` (uses [`packaging/PKGBUILD`](packaging/PKGBUILD)).
+- **Debian/Ubuntu:** `.deb` is built with [`cargo-deb`](https://github.com/kornelski/cargo-deb) from the `[package.metadata.deb]` block in `Cargo.toml`. Build inside a Debian/Ubuntu environment so the binary links that distro's glibc.
+- **Windows:** see [`docs/WINDOWS.md`](docs/WINDOWS.md).
+
+## License
+
+PeerSpeak is licensed under the [MIT License](LICENSE), © 2026 mollusk.
+
+Third-party components bundled with PeerSpeak (the Rust dependency tree, the
+statically bundled Opus codec on some builds, and embedded fonts) are all under
+permissive licenses; their texts and a full dependency manifest are collected in
+[`THIRD_PARTY_LICENSES`](THIRD_PARTY_LICENSES).
@@ -1,80 +0,0 @@
-# Example entry in an antigravity.toml configuration file
-[agent]
-model = "gemini-3.5-flash"
-system_instruction = """
-You are a senior-level, terminal-native Rust systems engineer and an expert programming assistant. Your goal is to help me design, build, and refactor a decentralized, peer-to-peer (P2P) voice communication application modeled after Mumble, utilizing the Iroh network stack for NAT holepunching and QUIC stream orchestration.
-
-### 0. How You Work — Operating Principles (read first)
-Capability is not the constraint here; judgment is. These govern HOW you approach every task in this repo, and the project-specific sections below make them concrete.
- **Understand before you act.** Read the actual code and the local docs (Sections 1, 8) before changing anything — never reason from memory about an API, type, or signature; open it and confirm. This is Rule 1 made operational. Orient in the codebase (Section 5) and honor its trait boundaries and idioms — you are editing a mature codebase, not starting fresh, so match its naming, error-handling, and comment density.
- **Measure before you theorize — the single most important habit.** When debugging, get EVIDENCE before asserting a cause: instrument it, log it, reproduce it, read the real output. A plausible-sounding mechanism is a hypothesis, not a diagnosis. If the data contradicts your theory, drop the theory — do not bend the evidence to fit it. (The playback-crackle bug was only solved once the actual per-cycle PipeWire quantum was measured; every "reasoned" guess before that missed.)
- **Root-cause, don't patch symptoms.** Trace a bug to the exact mechanism that produces it; a fix you cannot explain is a coincidence waiting to break. Make the smallest change that addresses the real cause — don't expand scope or refactor unasked. Flag adjacent problems; don't silently fold them in.
- **"Compiles" and "tests pass" are NOT "it works."** These are three separate claims — builds-clean, tests-green, and field-verified-by-running-it — and you must state which you have actually reached (this reinforces Section 7). For this app, "verified" means a real run/call was observed behaving correctly (clean audio heard by ear, a reconnect watched in the logs), not that the suite passed. Never announce a fix as working on tests alone; explicitly label untested or tests-only work as "unverified."
- **Surface the forks on real decisions.** When a task has genuine tradeoffs (architecture, a new dependency, an irreversible change), lay out the realistic options with their costs and let me choose BEFORE you build. For a choice with an obvious default and no downside, just pick it, say what you picked, and proceed — don't manufacture decisions.
- **Report honestly.** If it failed, say so and show the evidence. If you assumed or skipped something, say that. When something is genuinely done and verified, say so plainly without hedging. If new evidence contradicts something you stated confidently, correct yourself explicitly. "I verified X" and "I believe X" are different claims — use the right one. Never fabricate APIs, file paths, or results; if unsure, say "I'm not sure" and go confirm (Rule 1).
- **Treat dependencies as a liability.** Prefer the standard library, tools already on the system, or a few lines of your own over pulling in a crate — I vet dependencies for supply-chain risk. Justify any addition, and default to safe Rust (Rule 3).
- **Know when NOT to do what I ask.** Doing the task is the default, but stop and confirm or push back when: the action is hard to reverse or outward-facing — pushing, publishing, deploying the binary to the other machine, deleting/overwriting files you did not create (confirm first; for git commits specifically, see Rule 4); the request rests on a false premise or contradicts what you find in the code (surface that instead of plowing ahead); compliance would introduce real risk — data loss, a security/privacy regression (e.g. changing the `RelayNoDiscovery` default, see Section 6), an `unsafe` block, or a heavy dependency (name the risk and offer a safer path); or the scope is ambiguous (confirm rather than over-building — build X, not X plus extras). Don't merely comply and don't merely refuse — offer the better route.
- **Work in checkpoints; keep state durable.** Give a short plan and a rough scope/effort estimate up front so I can redirect or defer (I watch a daily usage budget). Phase large work so it can pause cleanly. The handoff log (Section 8) is the durable record across sessions — read it first, update it when you finish meaningful work.
- **Follow the collaboration protocol (read first, every task).** Before starting any task, read `/home/mollusk/Documents/handoff-docs/Gemini/peerspeak/operating-agreement.md`. It defines how we work as a team: a senior engineer designs and reviews the work, tasks are assigned to you in `next-task.md`, and you report back in `task-report.md`. It is in force this session and every session until that file says otherwise.
-
-### 1. Context and Knowledge Base
-You have immediate, local access to the definitive Rust documentation suite located at the absolute path: `/home/mollusk/Documents/rust_docs/`. 
-Before answering highly complex questions, writing macros, or optimizing code, you must reference these specific resources:
- Syntax, language invariants, and semantics: `/home/mollusk/Documents/rust_docs/rust-reference/`
- Idiomatic structural choices, patterns, and logic: `/home/mollusk/Documents/rust_docs/the-book/`
- Pointer manipulation, data layout, and undefined behavior: `/home/mollusk/Documents/rust_docs/rust-nomicon/`
- API design, trait implementations, and naming conventions: `/home/mollusk/Documents/rust_docs/rust-api-guidelines/`
-
-### 2. Specialized Architectural Constraints
- **P2P Audio Boundary Isolation:** We are utilizing a decoupled architecture. The asynchronous network runtime (Tokio + Iroh) must be kept strictly separated from the real-time audio thread pool (PipeWire). Communication between the Iroh network consumers and the PipeWire audio streams must happen exclusively via bounded, lock-free SPSC (Single-Producer Single-Consumer) or MPSC ring buffers.
- **The "No-Alloc" Audio Rule:** Code generated for the audio processing callback or multi-stream mixer must be strictly safe and real-time safe. It must contain zero heap allocations, zero blocking synchronization primitives (no standard Mutex/RwLock), and zero blocking file/network I/O.
- **Iroh Topology:** We handle voice channels by treating every peer node as a full-mesh target. Leverage Iroh's unreliable QUIC Datagrams for raw, low-latency audio packet delivery and Iroh-Gossip (or bi-directional streams) for state synchronization (room mapping, mute states, and peer metadata).
-
-### 3. Behavioral Boundaries and Accuracy
- **Rule 1 (Absolute Ground Truth):** Never guess or hallucinate syntax rules, compiler behavior, or API surfaces. If you are not 100% sure about a specific language feature, macro expansion, standard library behavior, or dependency change, stop and explicitly state: "I'm actually not sure about that."
- **Rule 2 (No "C in Rust"):** Do not write C-style logic wrapped in Rust syntax. Prioritize idiomatic Rust patterns (e.g., using algebraic data types, proper trait bounds, combinators like `.map()` or `.and_then()`, and precise error handling with `Result` and `Option`).
- **Rule 3 (Safe by Default):** Always default to safe, idiomatic Rust code. Do not introduce an `unsafe` block unless it is explicitly requested, or unless you can rigorously prove using *The Rustonomicon* constraints that safe Rust cannot achieve the required performance boundary.
- **Rule 4 (Git Commit Policy):** When a feature is completed, you must always ask the user for permission before committing files to git. Never commit files automatically.
-
-### 4. Output Requirements
- **Contextual Clarity:** When providing a solution that relies on advanced language mechanics (like complex lifetimes, custom traits, or macro rules), briefly cite which local resource or module layout you used to verify the approach.
- **Code Generation:** Provide clean, production-ready code with minimal boilerplate. Use standard formatting rules (`rustfmt` styles). Include brief, high-value comments for complex borrowing logic or lifetime annotations.
- **Error Resolution:** If asked to fix a compiler or borrow-checker error, explain *why* the error occurred in terms of Rust's core memory model (ownership/borrowing/lifetimes) before providing the refactored code.
-
-### 5. Project Map — Where Things Live
-This is a mature codebase, not a greenfield project. Orient yourself in it before editing. The architecture is trait-based so implementations stay swappable; honor the boundaries.
- `src/network/mod.rs` — the `NetworkTransport` and `RoomState` traits + shared types (`PeerState`, `RoomEvent`, `ConnEvent`, `PeerSpeakTicket`). Start here to understand the seams.
- `src/network/iroh_impl.rs` — the audio transport. Per-peer **supervisor** tasks own each connection's whole lifecycle; QUIC datagrams carry audio. This is the most subtle file — see Section 6.
- `src/network/gossip.rs` — `iroh-gossip` room state: presence roster, mute/metadata sync, join/leave, address announcements feeding the `MemoryLookup`.
- `src/core/mod.rs` — the coordinator: wires capture→encode→broadcast and receive→jitter→decode→mix→playback, and bridges room/transport events to the UI. Runs on its own Tokio runtime thread.
- `src/core/jitter.rs` — per-peer jitter buffer (reorder + fixed playout delay + Opus PLC on loss). Unit-tested.
- `src/audio/{pipewire_impl.rs,pw_cli.rs}` — PipeWire capture/playback in the real-time path; device enumeration via `pw-cli`.
- `src/codec/opus_impl.rs` — Opus encode/decode behind the `AudioCodec` trait.
- `src/app/mod.rs` — the `iced` GUI (Catppuccin-styled). `src/config.rs` — persisted settings (`~/.config/peerspeak/config.json`).
- `tests/transport_loopback.rs` — end-to-end transport tests over real localhost iroh endpoints. `src/bin/test_net.rs` — a manual two-node harness.
-
-### 6. Audio-Networking Invariants (hard-won — each of these maps to a real bug that was fixed)
-Treat these as load-bearing. They are non-obvious and were violated in earlier iterations.
- **One shared connection per peer pair, deterministic initiator.** The lower `EndpointId` (string comparison) **dials**; the higher **accepts**. Both sides call `connect_peer`; the rule dedups so exactly one bidirectional QUIC connection forms per pair. Never open a second per-direction connection, and never spawn a connection (or a task) per audio frame — use the long-lived per-peer send path.
- **The per-peer supervisor owns connect → run → reconnect.** All of a peer's connection lifecycle lives in one `supervise` task (`iroh_impl.rs`). Don't scatter dialing/reconnect logic across call sites; reconnection must re-apply the same deterministic-initiator rule so the single shared connection re-forms.
- **Any detached task holding a `Connection` clone MUST be abort-on-drop.** A live `Connection` clone keeps the QUIC link open. If send/read loops aren't torn down on peer-removal/reconnect, the link never actually closes and the peer only notices at the ~30s idle timeout. Scope them in `AbortOnDrop` guards tied to the live-link block.
- **A silent handle-drop is NOT a close.** Dropping all `Connection` handles does not promptly notify the peer — they find out only at the QUIC idle timeout (~30s). Only `Connection::close()` sends an immediate `CONNECTION_CLOSE`. This matters for both teardown and for writing tests that need a prompt drop.
- **Retain each peer's full `EndpointAddr` and dial it directly; do not lean on `MemoryLookup` alone.** Dialing by bare `EndpointId` forces iroh to resolve via the gossip-fed `MemoryLookup`. A transient drop that fires a gossip `Leave`/`NeighborDown` purges that entry, and the dialer then redial-loops forever with "no address." The transport keeps each peer's full address (relay + direct addrs) for the supervisor's lifetime, refreshed on every re-announce, and dials it directly. (This was the 2026-05-31 fix.)
- **Presence layer ≠ transport layer.** The gossip roster (who's in the room) is independent of a peer's audio-link state. A peer can be present with its audio link down/reconnecting. Keep the two UI signals distinct (`RoomEvent` vs `ConnEvent`); don't infer one from the other.
- **Every audio datagram carries a 4-byte little-endian sequence header.** The receiver feeds `(seq, payload)` into the per-peer `JitterBuffer`, which reorders, holds a fixed playout delay, and invokes Opus PLC (`decode(None)`) on gaps. Never decode datagrams directly in arrival order, and size PLC to one 20ms frame.
- **`broadcast()` must never block the capture/encode thread.** It is called from the non-async audio path. Use `try_send` into shallow per-peer queues and **drop on full** — stale audio is worthless and a slow peer must never stall encoding. No `await`, no large/unbounded queues here.
- **Real-time audio path (reaffirming Section 2):** zero heap allocation, zero blocking locks (no `Mutex`/`RwLock`), zero I/O inside the PipeWire callback/mixer. Cross the async↔RT boundary only through bounded lock-free ring buffers.
- **Throttle high-rate UI events.** Don't forward per-20ms-tick events (e.g. `AudioLevels`, ~50/sec) straight to the GUI; coalesce with peak-hold to ~10/sec.
- **Privacy posture is intentional.** Default `NetworkMode` is `RelayNoDiscovery`: keep the n0 relay (NAT traversal + re-reachability anchor) but emit **no** DNS presence beacon. Do not change the default to anything that publishes presence. Decision on record: we are **not** self-hosting a relay.
-
-### 7. Testing & Field-Verification Gotchas
- **The loopback/integration tests use stable, fixed addresses**, so they silently miss address-eviction and new-address bugs. When testing reconnect resilience, **starve every address source** (empty the `MemoryLookup` *and* disable the relay) to force the retained-address path. Merely calling `remove_endpoint_info` is a **false** test: iroh internally caches the path from a recent live connection, so the reconnect still succeeds even with the bug present.
- **Two instances on one host are INVALID for outage/disconnect tests.** Docker bridges (`172.x`) plus loopback keep them talking even with the main NIC down. Use two real machines, or two network namespaces joined by a single `veth` you can `ip link set ... down`.
- **To drive a prompt link drop in a test, explicitly `close()` the connection** — a silent drop waits out the ~30s idle timeout (see Section 6).
- **Before declaring anything done:** `cargo clippy --all-targets` must be clean (zero warnings) and `cargo test` must pass. Distinguish "tests-green" from "field-verified" — say which one you actually have.
-
-### 8. Offline Docs for the Network/Audio Stack
-In addition to the general Rust docs in Section 1, the **API docs for this project's dependencies** (iroh, iroh-gossip, tokio, opus, pipewire, iced, …) are generated locally at `/home/mollusk/Documents/peerspeak_docs/`. Grep/read these instead of probing the web — e.g. confirm `Endpoint::connect`'s signature or `MemoryLookup`'s methods there. The design blueprint is at `/home/mollusk/Documents/P2P_Voice_Chat_Blueprint.md`. A **living handoff log** is maintained at `/home/mollusk/Documents/handoff-docs/Gemini/peerspeak/handoff.md` — **read it first each session** for current state, recent commits, and known/open bugs, and append a dated entry when you finish meaningful work.
-
-Acknowledge these operational parameters, then orient yourself in the existing codebase (Section 5) and the handoff log (Section 8) before proposing or making changes. Summarize the current project state back to me and ask what we're tackling this session.
-"""
@@ -0,0 +1,22 @@
+use std::process::Command;
+
+fn main() {
+    println!("cargo:rerun-if-changed=.git/HEAD");
+    if let Ok(head) = std::fs::read_to_string(".git/HEAD")
+        && let Some(reference) = head.strip_prefix("ref: ")
+    {
+        println!("cargo:rerun-if-changed=.git/{}", reference.trim());
+    }
+
+    let short = Command::new("git")
+        .args(["rev-parse", "--short=8", "HEAD"])
+        .output()
+        .ok()
+        .filter(|output| output.status.success())
+        .and_then(|output| String::from_utf8(output.stdout).ok())
+        .map(|value| value.trim().to_string())
+        .filter(|value| !value.is_empty())
+        .unwrap_or_else(|| "unknown".to_string());
+
+    println!("cargo:rustc-env=PEERSPEAK_GIT_SHORT={short}");
+}
@@ -81,8 +81,8 @@ allow = [
 confidence-threshold = 0.8
 exceptions = []

-# peerspeak itself has no `license` field and is not published, so skip the
-# "unlicensed" check for our own (private) crate. Add a license to Cargo.toml
-# if/when this is ever published.
+# peerspeak is MIT-licensed (see Cargo.toml `license` + the LICENSE file) but is
+# not published to crates.io, so keep the private-crate skip for the
+# "unlicensed"/publish checks. MIT is already in the allow list above.
 [licenses.private]
 ignore = true
@@ -102,6 +102,7 @@ covers internals). When you ship a feature, add it here.
 | iroh QUIC transport | ✅ | |
 | Network mode picker | ✅ | `RelayNoDiscovery` (default), `N0Full`, `DirectOnly`. Takes effect next join. |
 | Retained-address reconnect | ✅ | Dials last-known full addr before falling back to bare id. |
+| Per-peer connection badge (direct/relay + RTT, hover for addr/loss/bitrate) | ✅ | Peer-card badge fed by a 1 Hz poll of the live audio link's selected QUIC path (`connection_stats` → `core::connstats::derive`). Field-verified on a real 2-machine call 2026-07-08. |
 | Reconnect + eviction model | ✅ | Incl. two-outage reconnect-eviction fix + regression test. |
 | Self-hosted relay | ❌ | Decided against — rely on n0 relays, `RelayNoDiscovery` default. |

@@ -1,19 +1,28 @@
 # PeerSpeak on Windows

-Current status: the Windows port cross-compiles to `x86_64-pc-windows-gnu` and the `.exe`
-launches under Wine. A real Windows/WASAPI host is still needed for the final audio-device
-checks listed below.
+Current status: PeerSpeak cross-compiles to `x86_64-pc-windows-gnu` from Linux and
+has passed an older native Windows 11 VM smoke test for launch, GUI render, call
+join, and audio flow. The build environment is **not** the Windows VM; current
+Windows binaries are built from Linux, normally inside the `peerspeak-win`
+distrobox or with the same GNU target environment.
+
+The Windows runtime still trails Linux in a few important areas. See the Claude
+handoff file `windows-parity-audit.md` for the full audit and task breakdown.

 ## What works today

 | Area | Status |
 |---|---|
-| GUI | Iced/wgpu builds and renders under Wine. |
-| Networking | Iroh QUIC transport and gossip compile on Windows. |
+| GUI | Iced/wgpu builds for Windows and rendered in the Windows 11 VM. |
+| Networking | Iroh QUIC transport and gossip compile on Windows; VM call reached two peers. |
 | Audio backend | `cpal` drives WASAPI capture/playback behind `AudioBackend`. |
+| Device selection | cpal enumerates input/output devices; see caveat below about stable IDs. |
+| Resampling/remap | WASAPI devices can run non-48 kHz formats; PeerSpeak converts at the backend boundary. |
 | Codec | Opus remains 48 kHz mono, 20 ms frames. |
-| Identity | `ring` identity generation/load is platform-neutral. |
+| Identity/config | Stored through `dirs` under the Windows profile. |
 | Chimes | Windows uses PowerShell `System.Media.SoundPlayer` for WAV playback. |
+| Game detection | Steam registry `RunningAppID` plus Toolhelp process-scan fallback compile on Windows. |
+| File dialogs | `rfd` uses the native Win32 dialog backend. |

 Windows paths are resolved through `dirs`:

@@ -23,55 +32,72 @@ Windows paths are resolved through `dirs`:

 ## Building

-### Native Windows
+### Cross-compile from Linux

-Install MSVC Build Tools and CMake, then build normally:
+Preferred local path:

-```powershell
-cargo build --release
+```sh
+distrobox enter peerspeak-win -- bash -lc '
+  cd ~/git/butter/peerspeak &&
+  RUSTC_BOOTSTRAP=1 ./win-cross-build.sh -Z build-std=std,panic_abort
+'
 ```

-If CMake is 4.x or newer, the vendored `opus`/`libopus` build may need:
+Equivalent direct command when the host has the GNU target, MinGW, `rust-src`, and
+CMake available:
+
+```sh
+CMAKE_POLICY_VERSION_MINIMUM=3.5 RUSTC_BOOTSTRAP=1 \
+  cargo build --release --target x86_64-pc-windows-gnu --bin peerspeak \
+  -Z build-std=std,panic_abort
+```
+
+`CMAKE_POLICY_VERSION_MINIMUM=3.5` is required with host CMake 4.x because the
+vendored Opus build used by `audiopus_sys` still declares an old minimum CMake
+version. Without that env var, the Windows build/check fails during Opus configure.
+
+### Native Windows
+
+A native MSVC build is not the active development path. If used, install MSVC Build
+Tools and CMake, then build normally:

 ```powershell
 $env:CMAKE_POLICY_VERSION_MINIMUM = "3.5"
 cargo build --release
 ```

-### Cross-compile from Linux
-
-The current dev path cross-compiles from an Arch environment to the GNU Windows target:
-
-```sh
-rustup target add x86_64-pc-windows-gnu
-sudo pacman -S mingw-w64-gcc cmake
-CMAKE_POLICY_VERSION_MINIMUM=3.5 cargo build --release --target x86_64-pc-windows-gnu --bin peerspeak
-```
-
-Wine is useful for launch/render smoke tests, but it is not a substitute for a real
-Windows audio-device pass. The deeper migration plan (phases, decisions, the opus build
-spike) lives in the maintainer's handoff docs, outside the repo.
-
 ## First run and networking

-Expect a Windows Firewall prompt the first time the app opens network sockets. Allow it:
-PeerSpeak uses UDP for QUIC, plus relay traffic when direct NAT traversal is not available.
+Expect a Windows Firewall prompt the first time the app opens network sockets, or
+use the Inno installer option that pre-adds a firewall allow rule. PeerSpeak uses
+UDP for QUIC plus relay traffic when direct NAT traversal is unavailable.

-The default network mode keeps the n0 relay available for NAT traversal without publishing
-presence to n0 DNS. Direct peer-to-peer paths may work when both networks allow them; relayed
-connections are expected and valid.
+The default network mode keeps the n0 relay available for NAT traversal without
+publishing presence to n0 DNS. Relayed connections are expected and valid.

 ## Known gaps

 | Item | Status |
 |---|---|
-| Echo cancellation | Linux-only PipeWire feature. The Windows UI shows it disabled as unavailable. |
-| Screen share | Requires a Windows `pixelpass.exe` on `PATH` or a configured override. |
-| Chimes | Now routed through Windows `SoundPlayer`; needs a real Windows host to audibly verify. |
-| Resampling/device format | Cross-compiled. cpal/WASAPI now chooses native 48 kHz when available and otherwise resamples/remaps at the device boundary; needs real Windows hardware audio verification. |
-| Device persistence | Open. WASAPI friendly names may duplicate or change across driver/profile changes. |
-| Playback pacing | Cross-compiled. The fixed playback target under WASAPI shared mode still needs real-hardware verification with `audio_probe`. |
+| Echo cancellation | Linux-only today. The Windows UI shows it disabled as unavailable. |
+| Screen share | Blocked by PixelPass, which is currently Linux-only in practice. PeerSpeak can spawn `pixelpass.exe`, but there is no Windows PixelPass host/viewer parity yet. |
+| Device persistence | Uses cpal friendly names as keys. These can duplicate or change across Windows driver/profile changes; stable WASAPI endpoint IDs are still needed. |
+| Release hygiene | Keep `.iss` and installer output in sync with `Cargo.toml`; rebuild Windows artifacts during each release. |
+| Runtime coverage | The Windows VM smoke test proved an older tester build. Current `main` needs a fresh VM smoke matrix before calling parity current. |

-Before calling Windows support done, verify a real Windows machine can create/join a room,
-capture mic audio, hear remote audio, select devices, restart with selections preserved, and
-play notification chimes.
+## Current smoke checklist
+
+Before calling a Windows build current, verify on the Windows VM or real Windows
+hardware:
+
+- Launch current `peerspeak.exe`; GUI renders and settings open.
+- Run `audio_probe.exe 440 30`; listen for glitches and inspect `playout-health`.
+- Create/join a Linux <-> Windows room; confirm mic and playback both directions.
+- Select input/output devices, restart, and confirm selections persist or fall back clearly.
+- Play chimes and custom chime paths.
+- Send chat, image/file attachments, and save an attachment through the native dialog.
+- Import/play/share/listen to music from Windows file paths.
+- Record mixed/stems/both and inspect the WAV output path.
+- Exercise friends/presence/recents and the clock-skew banner.
+- Test Steam and non-Steam game detection on a real Windows Steam install.
+- Install/upgrade/uninstall through the Inno installer, including firewall rule cleanup.
@@ -1,12 +1,12 @@
 # Maintainer: mollusk <jitty+lc1iz0dc@protonmail.com>
 pkgname=peerspeak-git
 _pkgname=peerspeak
-pkgver=0.3.0.r229.g7fb1c96
+pkgver=0.6.2.r319.g8014edf
 pkgrel=1
 pkgdesc="Decentralized peer-to-peer voice chat (Rust/iroh/PipeWire/Opus/iced)"
 arch=('x86_64')
 url="https://gitbutter.xyz/mollusk/peerspeak"
-license=('custom')
+license=('MIT')
 depends=('pipewire' 'opus')
 makedepends=('git' 'cargo' 'pkgconf')
 optdepends=('pixelpass: screen sharing inside a room'
@@ -14,7 +14,7 @@ optdepends=('pixelpass: screen sharing inside a room'
 provides=('peerspeak')
 conflicts=('peerspeak')
 options=('!lto' '!debug')
-source=("$_pkgname::git+ssh://git@gitbutter.xyz/mollusk/peerspeak.git")
+source=("$_pkgname::git+https://gitbutter.xyz/mollusk/peerspeak.git")
 sha256sums=('SKIP')

 pkgver() {
@@ -38,6 +38,11 @@ build() {
  export CARGO_HOME="$srcdir/cargo-home"
  export RUSTUP_TOOLCHAIN=stable
  export CARGO_TARGET_DIR=target
+  # Strip the build directory out of paths embedded in the binary (Rust bakes
+  # source paths into panic/backtrace metadata that survives stripping), so the
+  # package doesn't reference $srcdir. One remap covers our sources and the
+  # vendored deps, since CARGO_HOME lives under $srcdir too.
+  export RUSTFLAGS="${RUSTFLAGS:-} --remap-path-prefix=$srcdir=/"
  cargo build --frozen --release --bin "$_pkgname"
 }

@@ -65,4 +70,9 @@ package() {
    install -Dm644 "assets/icons/$_pkgname-$s.png" \
      "$pkgdir/usr/share/icons/hicolor/${s}x${s}/apps/$_pkgname.png"
  done
+
+  # License + third-party attribution notices.
+  install -Dm644 LICENSE "$pkgdir/usr/share/licenses/$_pkgname/LICENSE"
+  install -Dm644 THIRD_PARTY_LICENSES \
+    "$pkgdir/usr/share/licenses/$_pkgname/THIRD_PARTY_LICENSES"
 }
@@ -0,0 +1,4 @@
+.tools/
+AppDir/
+*.AppImage
+squashfs-root/
@@ -0,0 +1,11 @@
+#!/bin/sh
+# AppRun for the PeerSpeak AppImage.
+#
+# PeerSpeak bundles the pixelpass screen-share helper in usr/bin. We prepend our
+# own usr/bin to PATH so peerspeak's $PATH lookup for `pixelpass` finds the
+# bundled copy, while the host's tools (gst-launch-1.0, pactl, mpv — which
+# pixelpass in turn shells out to) remain reachable via the appended host PATH.
+# That no-sandbox spawning is exactly why this app suits AppImage over Flatpak.
+HERE="$(dirname "$(readlink -f "$0")")"
+export PATH="$HERE/usr/bin:$PATH"
+exec "$HERE/usr/bin/peerspeak" "$@"
@@ -0,0 +1,76 @@
+# PeerSpeak AppImage
+
+A "thin" AppImage: the `peerspeak` binary, the bundled `pixelpass` screen-share
+helper, a launcher (`AppRun`), and the desktop entry + icon. Run
+`./build-appimage.sh` to produce `peerspeak-<version>-x86_64.AppImage`.
+
+## Why thin, and why pixelpass is bundled
+
+PeerSpeak owns voice; **pixelpass** owns pixels. They are never Cargo
+dependencies of each other — peerspeak shells out to the `pixelpass` binary over
+its CLI. The AppImage co-locates `pixelpass` in `usr/bin`, and `AppRun` prepends
+`usr/bin` to `PATH`, so peerspeak's normal `$PATH` lookup finds it with no code
+change. Joe gets one file, and screen-share works out of the box.
+
+Almost nothing is bundled: peerspeak's own assets (notification WAVs, avatar
+presets, window icon, fonts) are `include_bytes!`-embedded, and the graphics
+stack (`libGL`, `libvulkan`, `libwayland-*`, `libxkbcommon`, X11) is dlopen'd at
+runtime and on the AppImage excludelist because it must match the host driver.
+So the image carries just the two binaries plus a handful of small libs.
+
+## Host requirements
+
+The AppImage runs on any reasonably current glibc-based distro that has:
+
+- **A Vulkan-capable GPU + driver** (peerspeak's iced/wgpu renderer). Mesa/RADV
+  on AMD/Intel or the NVIDIA driver all work.
+- **PipeWire** (with the PulseAudio shim, for `pactl`).
+- For **screen-share only** — pixelpass shells out to these on the host `PATH`;
+  it prints the exact package names for your distro if any are missing:
+  - **GStreamer + plugins** (`gst-launch-1.0`/`gst-inspect-1.0`, base,
+    good/bad/ugly, libav, and the PipeWire plugin),
+  - **mpv** (or vlc) for the viewer side,
+  - on X11, `xwininfo` for single-window capture.
+
+On Arch/Artix that is one pacman line, e.g.:
+
+```sh
+sudo pacman -S gstreamer gst-plugins-base gst-plugins-good gst-plugins-bad \
+  gst-plugins-ugly gst-libav gst-plugin-pipewire mpv xorg-xwininfo libpulse
+```
+
+(Add `gstreamer-vaapi` for hardware H.264 encode on AMD/Intel; the software
+x264 path always works. On XLibre / X11 the capture path uses `ximagesrc` and
+needs no XDG portal — no systemd required.)
+
+## Building for broad compatibility (glibc baseline)
+
+An AppImage requires a host glibc **at least as new** as the build host's. Built
+on a rolling distro (glibc 2.43) it only runs on equally-new systems. Build
+inside **Ubuntu 24.04** (glibc 2.39, PipeWire 1.0.5) for wide reach — pixelpass's
+`pipewire` crate binds the system PipeWire headers and needs PipeWire >= 1.0, so
+the older Debian 12 `peerspeak-bookworm` box (PW 0.3.65) cannot build it. 2.39
+covers Debian 13+, Fedora 40+, and current rolling distros.
+
+```sh
+# One-time: an Ubuntu 24.04 distrobox that reuses the host rustup toolchain.
+distrobox create --yes --image ubuntu:24.04 --name peerspeak-appimage
+distrobox enter peerspeak-appimage -- sudo apt-get update
+distrobox enter peerspeak-appimage -- sudo apt-get install -y \
+  build-essential cmake clang libclang-dev pkg-config \
+  libpipewire-0.3-dev libspa-0.2-dev libasound2-dev libxcb1-dev \
+  curl ca-certificates file patchelf git
+
+# Build (the host's ~/.rustup toolchain is glibc-2.17-baseline, so it runs in the
+# box; isolated CARGO_TARGET_DIRs keep it off the host target/):
+distrobox enter peerspeak-appimage -- env \
+  PATH="$HOME/.rustup/toolchains/stable-x86_64-unknown-linux-gnu/bin:$PATH" \
+  ./packaging/appimage/build-appimage.sh
+```
+
+## Caveats
+
+- **Hardware encode (VAAPI)** uses the host GPU driver and can't be bundled; the
+  software x264 path always works.
+- The bundled `pixelpass` is built headless (no `gui` feature) — it is only ever
+  driven by peerspeak, never launched standalone from this image.
@@ -0,0 +1,89 @@
+#!/usr/bin/env bash
+# Build a "thin" PeerSpeak AppImage that also bundles the pixelpass screen-share
+# helper.
+#
+# PeerSpeak is an iced/wgpu GUI app; pixelpass is the separate screen-share
+# orchestrator peerspeak shells out to (never a Cargo dependency). Both link
+# almost nothing — the graphics stack (libGL, libvulkan, wayland, xkbcommon,
+# X11) is dlopen'd at runtime and is on the AppImage excludelist because it must
+# match the host driver, and pixelpass's capture/encode tools (gst-launch-1.0,
+# pactl, mpv) are expected on the host PATH. So the AppImage carries just the two
+# binaries plus their handful of non-excludelisted libs. The custom AppRun
+# prepends usr/bin to PATH so peerspeak's own $PATH lookup finds the bundled
+# pixelpass, while the host's tools stay reachable.
+#
+# All runtime assets (notification WAVs, avatar presets, window icon, fonts) are
+# include_bytes!-embedded in the peerspeak binary, so nothing else is bundled.
+#
+# Usage:   packaging/appimage/build-appimage.sh
+# Output:  packaging/appimage/peerspeak-<version>-x86_64.AppImage
+#
+# Build inside an Ubuntu 24.04 distrobox (glibc 2.39, PipeWire 1.0.5) for broad
+# reach — pixelpass's `pipewire` crate needs PipeWire >= 1.0 headers, so the
+# older peerspeak-bookworm box (PW 0.3.65) cannot build it. The 2.39 baseline
+# covers Debian 13+, Fedora 40+, and all current rolling distros. See README.md.
+set -euo pipefail
+
+here="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+repo="$(cd "$here/../.." && pwd)"
+tools="$here/.tools"
+appdir="$here/AppDir"
+mkdir -p "$tools"
+
+# linuxdeploy is itself an AppImage; run it without FUSE so this works in a
+# container / on CI without libfuse2.
+export APPIMAGE_EXTRACT_AND_RUN=1
+VERSION="$(grep -m1 '^version' "$repo/Cargo.toml" | sed -E 's/.*"(.*)".*/\1/')"
+export VERSION
+
+# Isolated target dirs so an old-glibc box build never clobbers the host target/.
+cache="${PEERSPEAK_APPIMAGE_CACHE:-$HOME/.cache/peerspeak-appimage}"
+ps_target="$cache/peerspeak-target"
+pp_target="$cache/pixelpass-target"
+
+# The pixelpass screen-share helper we bundle. Sibling checkout by default.
+pixelpass_repo="${PIXELPASS_REPO:-$repo/../pixelpass}"
+if [ ! -d "$pixelpass_repo" ]; then
+  echo "!! pixelpass repo not found at $pixelpass_repo (set PIXELPASS_REPO)" >&2
+  exit 1
+fi
+
+echo ">> building peerspeak (release)"
+( cd "$repo" && CARGO_TARGET_DIR="$ps_target" cargo build --release )
+ps_bin="$ps_target/release/peerspeak"
+
+# Headless pixelpass: peerspeak drives it via `--host`/viewer + `--output json`,
+# never its GUI, so the default (no `gui` feature) keeps the GL toolkit out.
+echo ">> building pixelpass (release, headless) from $pixelpass_repo"
+( cd "$pixelpass_repo" && CARGO_TARGET_DIR="$pp_target" cargo build --release )
+pp_bin="$pp_target/release/pixelpass"
+
+echo ">> fetching linuxdeploy"
+ld="$tools/linuxdeploy-x86_64.AppImage"
+if [ ! -x "$ld" ]; then
+  curl -fL --retry 3 -o "$ld" \
+    "https://github.com/linuxdeploy/linuxdeploy/releases/download/continuous/linuxdeploy-x86_64.AppImage"
+  chmod +x "$ld"
+fi
+
+echo ">> assembling AppDir"
+rm -rf "$appdir"
+mkdir -p "$appdir/usr/bin"
+install -m755 "$ps_bin" "$appdir/usr/bin/peerspeak"
+install -m755 "$pp_bin" "$appdir/usr/bin/pixelpass"
+
+echo ">> running linuxdeploy (bundles libs, builds the AppImage)"
+# -e (repeated): analyse both binaries for libraries to bundle; excludelisted
+#   graphics/glibc libs are skipped. -d/-i: desktop entry + icon.
+# --custom-apprun: our launcher that puts the bundled pixelpass on PATH.
+( cd "$here" && OUTPUT="peerspeak-${VERSION}-x86_64.AppImage" "$ld" \
+    --appdir "$appdir" \
+    -e "$appdir/usr/bin/peerspeak" \
+    -e "$appdir/usr/bin/pixelpass" \
+    -d "$repo/packaging/peerspeak.desktop" \
+    -i "$repo/assets/icons/peerspeak-256.png" \
+    --icon-filename peerspeak \
+    --custom-apprun "$here/AppRun" \
+    --output appimage )
+
+echo ">> done: $here/peerspeak-${VERSION}-x86_64.AppImage"
@@ -0,0 +1,87 @@
+# Debian / Ubuntu `.deb` build
+
+This documents how the `peerspeak_*.deb` is produced, so the deb path is as
+self-documenting as the Arch (`packaging/PKGBUILD`) and AppImage paths.
+
+The deb **recipe itself** lives in-repo as the `[package.metadata.deb]` block in
+the top-level `Cargo.toml` (cargo-deb's equivalent of a PKGBUILD). This file
+documents only the **build environment**, which is otherwise undiscoverable from
+a fresh clone.
+
+## TL;DR
+
+```sh
+# one-time: create + provision the build box (see "Build environment" below)
+distrobox enter peerspeak-bookworm -- bash -lc '
+  source ~/.cargo/env
+  cd ~/git/butter/peerspeak
+  export CARGO_TARGET_DIR=~/.cache/cargo-deb-targets/peerspeak   # MANDATORY, see below
+  cargo deb
+'
+# output: $CARGO_TARGET_DIR/debian/peerspeak_<version>-1_amd64.deb
+```
+
+## Build environment
+
+- **Base: a Debian 12 (bookworm) distrobox named `peerspeak-bookworm`.**
+  Created with `distrobox create --name peerspeak-bookworm --image debian:12`.
+  Bookworm ships **glibc 2.36**, which sets the widest practical compatibility
+  floor (see "glibc floor" below).
+- **NEVER build the `.deb` on the Arch host.** Two independent reasons:
+  1. The Arch host's glibc is far newer, so the resulting `.deb` would demand a
+     glibc no normal Debian/Ubuntu user has, and ships an empty `Depends`.
+  2. distrobox shares `$HOME` (and therefore the repo's `target/`) with the host,
+     so a host build links Arch-compiled C objects into the "Debian" binary.
+
+### One-time provisioning inside the box
+
+```sh
+distrobox enter peerspeak-bookworm
+sudo apt update
+sudo apt install -y build-essential pkg-config clang libclang-dev \
+    libpipewire-0.3-dev libopus-dev libasound2-dev libxcb1-dev
+# clang/libclang -> pipewire-sys bindgen ; libxcb1-dev -> link
+curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y
+source ~/.cargo/env
+cargo install cargo-deb
+```
+
+### The mandatory separate `CARGO_TARGET_DIR`
+
+Because distrobox shares `$HOME`, the repo's default `target/` is the **same
+directory** the Arch host builds into. If you run `cargo deb` without overriding
+the target dir, cargo will happily reuse Arch-built `.o`/rlib artifacts and link
+them into the Debian binary, producing a `.deb` that crashes or demands the
+host's glibc.
+
+Always point the build at a box-local cache:
+
+```sh
+export CARGO_TARGET_DIR=~/.cache/cargo-deb-targets/peerspeak
+```
+
+(Run `cargo clean` first if you ever suspect a polluted target dir.)
+
+## glibc floor
+
+The `.deb` is built against the build box's glibc, which becomes the install
+floor (`libc6 (>= 2.36)` lands in `Depends` via `$auto`):
+
+| Build box            | glibc | Runs on                              |
+|----------------------|-------|--------------------------------------|
+| `debian:12` (current)| 2.36  | Debian 12+, Ubuntu 24.04+ (glibc ≥ 2.36) |
+| `ubuntu:26.04` (old) | 2.43  | Ubuntu 26.04+ only — too narrow, abandoned |
+
+If a friend is on something even older than Debian 12, drop the floor further by
+recreating the box from an older base image and rebuilding.
+
+## Runtime `Depends` / `Recommends`
+
+- `Depends = "$auto"` — cargo-deb runs `dpkg-shlibdeps`, which discovers the
+  linked shared libraries (PipeWire, Opus, ALSA, xcb, glibc, …) automatically.
+- `Recommends = "pixelpass, mpv"` — `pixelpass` provides in-room screen sharing
+  and `mpv` is the screen-share viewer (these are companion programs invoked as
+  subprocesses, not linked libraries, so they are Recommends not Depends).
+
+See `pixelpass`'s own `packaging/debian/README.md` for why **its** `Depends`
+lists the whole GStreamer stack explicitly.
@@ -1,112 +0,0 @@
-# Maintainer: mollusk <jitty+lc1iz0dc@protonmail.com>
-#
-# Test-pack split package: ONE `makepkg -si` builds + installs BOTH peerspeak
-# (voice chat) and pixelpass (screen sharing) from the public gitbutter repos
-# over https. pixelpass lands on /usr/bin so peerspeak's screen-share button
-# finds it. Shared version string is derived from peerspeak's git.
-#
-# Clone this repo and build from here:
-#   git clone https://gitbutter.xyz/mollusk/peerspeak.git
-#   cd peerspeak/packaging/test-pack
-#   makepkg -si
-pkgbase=peerspeak-git
-pkgname=('peerspeak-git' 'pixelpass')
-pkgver=0.1.0
-pkgrel=1
-arch=('x86_64')
-url="https://gitbutter.xyz/mollusk/peerspeak"
-license=('custom' 'MIT' 'Apache-2.0' 'OFL-1.1')
-makedepends=('git' 'cargo' 'pkgconf')
-options=('!lto' '!debug')
-source=("peerspeak::git+https://gitbutter.xyz/mollusk/peerspeak.git"
-        "pixelpass::git+https://gitbutter.xyz/mollusk/pixelpass.git#branch=main")
-sha256sums=('SKIP'
-            'SKIP')
-
-pkgver() {
-  cd "$srcdir/peerspeak"
-  # Shared across both split packages. 0.1.0.r<commits>.g<short-sha>.
-  printf '%s.r%s.g%s' \
-    "$(awk -F'\"' '/^version =/{print $2; exit}' Cargo.toml)" \
-    "$(git rev-list --count HEAD)" \
-    "$(git rev-parse --short HEAD)"
-}
-
-prepare() {
-  # Vendor deps up front so build() can run --frozen (no surprise network).
-  export CARGO_HOME="$srcdir/cargo-home"
-  local host; host="$(rustc -vV | sed -n 's/host: //p')"
-  cd "$srcdir/peerspeak";  cargo fetch --locked --target "$host"
-  cd "$srcdir/pixelpass";  cargo fetch --locked --target "$host"
-}
-
-build() {
-  export CARGO_HOME="$srcdir/cargo-home"
-  export RUSTUP_TOOLCHAIN=stable
-  export CARGO_TARGET_DIR=target
-
-  cd "$srcdir/peerspeak"
-  cargo build --frozen --release --bin peerspeak
-
-  cd "$srcdir/pixelpass"
-  # --features gui so the .desktop launcher (pixelpass --gui) works.
-  cargo build --frozen --release --features gui
-}
-
-check() {
-  export CARGO_HOME="$srcdir/cargo-home"
-  export RUSTUP_TOOLCHAIN=stable
-  # peerspeak library unit tests only — its integration suites bind real
-  # iroh/QUIC endpoints and fail in a sandboxed/offline build environment.
-  cd "$srcdir/peerspeak"
-  cargo test --frozen --release --lib
-}
-
-package_peerspeak-git() {
-  pkgdesc="Decentralized peer-to-peer voice chat (Rust/iroh/PipeWire/Opus/iced)"
-  depends=('pipewire' 'opus')
-  optdepends=('pixelpass: screen sharing inside a room'
-              'mpv: screen-share viewer (vlc is used as a fallback)')
-  provides=('peerspeak')
-  conflicts=('peerspeak')
-  license=('custom')
-
-  cd "$srcdir/peerspeak"
-  install -Dm755 "target/release/peerspeak" "$pkgdir/usr/bin/peerspeak"
-  install -Dm644 "packaging/peerspeak.desktop" \
-    "$pkgdir/usr/share/applications/peerspeak.desktop"
-
-  # Hicolor icon theme (scalable SVG + the rendered raster sizes).
-  install -Dm644 "assets/icons/peerspeak.svg" \
-    "$pkgdir/usr/share/icons/hicolor/scalable/apps/peerspeak.svg"
-  local s
-  for s in 16 24 32 48 64 128 256 512; do
-    install -Dm644 "assets/icons/peerspeak-$s.png" \
-      "$pkgdir/usr/share/icons/hicolor/${s}x${s}/apps/peerspeak.png"
-  done
-}
-
-package_pixelpass() {
-  pkgdesc='P2P screen sharing over iroh — no port forwarding, no signup'
-  depends=('gstreamer' 'gst-plugins-base' 'gst-plugins-good' 'gst-plugins-bad'
-           'gst-libav' 'gst-plugin-va' 'libpulse' 'hicolor-icon-theme'
-           'libglvnd' 'libxkbcommon' 'wayland')
-  optdepends=('mpv: recommended stream viewer (the GUI launches mpv)'
-              'vlc: alternative stream viewer'
-              'gst-plugins-ugly: software x264 encoding for `pixelpass --no-hwencode`'
-              'gst-plugin-pipewire: screen capture on Wayland sessions'
-              'xorg-xwininfo: share a single window on X11 (`pixelpass --window`)')
-  license=('MIT' 'Apache-2.0' 'OFL-1.1')
-
-  cd "$srcdir/pixelpass"
-  install -Dm0755 "target/release/pixelpass" "$pkgdir/usr/bin/pixelpass"
-  install -Dm0644 assets/pixelpass.desktop \
-    "$pkgdir/usr/share/applications/pixelpass.desktop"
-  install -Dm0644 assets/pixelpass.svg \
-    "$pkgdir/usr/share/icons/hicolor/scalable/apps/pixelpass.svg"
-  install -Dm0644 README.md "$pkgdir/usr/share/doc/pixelpass/README.md"
-  install -Dm0644 LICENSE-MIT "$pkgdir/usr/share/licenses/pixelpass/LICENSE-MIT"
-  install -Dm0644 LICENSE-APACHE "$pkgdir/usr/share/licenses/pixelpass/LICENSE-APACHE"
-  install -Dm0644 assets/NotoSans-OFL.txt \
-    "$pkgdir/usr/share/licenses/pixelpass/NotoSans-OFL.txt"
-}
@@ -1,52 +0,0 @@
-# PeerSpeak + PixelPass — CachyOS/Arch test pack
-
-A single **split PKGBUILD** that builds the latest code from the public gitbutter
-repos and installs **both** programs at once:
-
- `peerspeak` — decentralized P2P voice chat
- `pixelpass` — P2P screen sharing (peerspeak launches it for the screen-share button)
-
-## Build & install (one command)
-
-```sh
-git clone https://gitbutter.xyz/mollusk/peerspeak.git
-cd peerspeak/packaging/test-pack
-makepkg -si
-```
-
-`makepkg -si` auto-installs every dependency via pacman before building —
-including the Rust toolchain itself (the `cargo` makedepend is provided by the
-`rust` package), `git`, `pkgconf`, pipewire + opus for peerspeak, and the
-gstreamer/VA-API stack for pixelpass. The only prerequisite is the `base-devel`
-group (which provides `makepkg`). If you already use `rustup`, that satisfies the
-`cargo` makedepend and the `rust` package won't be pulled in — no conflict.
-
-When it finishes you'll have `peerspeak` and `pixelpass` on your PATH at
-`/usr/bin`. To rebuild later with fresh upstream code, re-run `makepkg -si`; the
-git sources re-pull `main` and the version bumps automatically.
-
-> Skip the test step with `makepkg -si --nocheck` for a faster build.
-
-## Running the cross-internet test
-
-1. Launch `peerspeak` on both machines.
-2. One person **creates** a room and shares the room code/ticket with the other.
-3. The other **joins** with that code.
-4. iroh does NAT hole-punching automatically; if a direct path can't be made it
-   falls back to a public n0 relay — **no port forwarding required**.
-5. Allow the app through any local firewall if prompted (outbound UDP / QUIC;
-   nothing needs to be opened inbound for relay mode).
-
-### What we're smoke-testing
- Two real humans, two networks, over the internet.
- Mic capture + remote playback both directions, no crackle/dropouts.
- Mute / deafen, push-to-talk.
- Text chat in-room.
- Avatars (presets + custom upload) show up on the other side.
- Screen share: click the screen-share control → it launches `pixelpass`; the
-  viewer opens in `mpv` on the receiving side.
- Notification chimes (join/leave/etc.).
- Leave / rejoin cleanly.
-
-If anything misbehaves, grab the log path peerspeak prints on startup and the
-exact repro steps.
@@ -8,7 +8,7 @@ it once, then you and I connect directly to each other.

 ## 1. Install it

-1. Double-click **`peerspeak-0.3.0-setup.exe`** (the file I sent you).
+1. Double-click **`peerspeak-<version>-setup.exe`** (the file I sent you).

 2. **Windows will probably show a blue "Windows protected your PC" warning.**
   This is normal — it shows up for any app that isn't from a big company with a
@@ -11,8 +11,9 @@ runtime, so there are no extra DLLs to bundle. The installer payload is just the

 ## Version compatibility

-The installer version tracks the crate version in `Cargo.toml` (currently
-**0.3.0**) — keep `MyAppVersion` in `peerspeak.iss` in sync when it changes.
+The installer version tracks the release version in `Cargo.toml` — keep
+`MyAppVersion` in `peerspeak.iss` in sync when cutting a release. Do not reuse an
+old installer filename after a crate-version bump.

 Per `VERSIONING.md`, a **MINOR** bump in `0.x` is a **breaking wire change**:
 peers on different MINOR versions can't connect (they fail fast at the
@@ -12,7 +12,7 @@
 ; (x86_64-pc-windows-gnu, statically linked -- no extra DLLs needed).

 #define MyAppName "PeerSpeak"
-#define MyAppVersion "0.3.0"
+#define MyAppVersion "0.6.3"
 #define MyAppPublisher "mollusk"
 #define MyAppExeName "peerspeak.exe"

@@ -40,6 +40,7 @@ enum ClipCommand {
    Resume,
    Seek(Duration),
    Stop,
+    SetVolume(f32),
 }

 /// Cheap, `Send` command handle for the dedicated playback thread.
@@ -51,13 +52,16 @@ pub struct ClipPlayer {
 impl ClipPlayer {
    /// Start the playback worker. The system output device is opened lazily on
    /// first Play, so merely launching PeerSpeak never claims another stream.
-    pub fn new() -> (Self, SharedClipStatus) {
+    ///
+    /// `initial_volume` is the universal gain (`1.0` = unity) applied to every
+    /// clip, restored from config so the level persists across sessions.
+    pub fn new(initial_volume: f32) -> (Self, SharedClipStatus) {
        let (command_tx, command_rx) = mpsc::channel();
        let status = Arc::new(Mutex::new(ClipStatus::default()));
        let worker_status = Arc::clone(&status);
        std::thread::Builder::new()
            .name("peerspeak-clip-player".to_string())
-            .spawn(move || playback_worker(command_rx, worker_status))
+            .spawn(move || playback_worker(command_rx, worker_status, initial_volume))
            .expect("failed to spawn clip playback thread");
        (
            Self {
@@ -94,11 +98,24 @@ impl ClipPlayer {
    pub fn stop(&self) {
        let _ = self.command_tx.send(ClipCommand::Stop);
    }
+
+    /// Set the universal playback gain (`1.0` = unity). Applies to the current
+    /// clip immediately and to every clip played afterwards.
+    pub fn set_volume(&self, volume: f32) {
+        let _ = self.command_tx.send(ClipCommand::SetVolume(volume));
+    }
 }

-fn playback_worker(command_rx: mpsc::Receiver<ClipCommand>, status: SharedClipStatus) {
+fn playback_worker(
+    command_rx: mpsc::Receiver<ClipCommand>,
+    status: SharedClipStatus,
+    initial_volume: f32,
+) {
    let mut output: Option<MixerDeviceSink> = None;
    let mut player: Option<Player> = None;
+    // Universal gain remembered across clips so a level set on one upload
+    // carries to the next; reapplied to each freshly connected player.
+    let mut volume = initial_volume.max(0.0);

    loop {
        match command_rx.recv_timeout(Duration::from_millis(100)) {
@@ -124,7 +141,9 @@ fn playback_worker(command_rx: mpsc::Receiver<ClipCommand>, status: SharedClipSt
                if output.is_none() {
                    match DeviceSinkBuilder::open_default_sink() {
                        Ok(sink) => {
-                            player = Some(Player::connect_new(sink.mixer()));
+                            let new_player = Player::connect_new(sink.mixer());
+                            new_player.set_volume(volume);
+                            player = Some(new_player);
                            output = Some(sink);
                        }
                        Err(error) => {
@@ -177,6 +196,12 @@ fn playback_worker(command_rx: mpsc::Receiver<ClipCommand>, status: SharedClipSt
                }
                reset(&status);
            }
+            Ok(ClipCommand::SetVolume(level)) => {
+                volume = level.max(0.0);
+                if let Some(player) = player.as_ref() {
+                    player.set_volume(volume);
+                }
+            }
            Err(mpsc::RecvTimeoutError::Disconnected) => break,
            Err(mpsc::RecvTimeoutError::Timeout) => {}
        }
@@ -578,7 +578,9 @@ fn choose_config(device: &Device, output: bool) -> Result<cpal::SupportedStreamC
    let pick = |channels: Option<u16>| {
        ranges
            .iter()
-            .find(|r| usable_range(r) && supports_48k(r) && channels.is_none_or(|c| r.channels() == c))
+            .find(|r| {
+                usable_range(r) && supports_48k(r) && channels.is_none_or(|c| r.channels() == c)
+            })
            .cloned()
    };

@@ -666,15 +668,30 @@ fn run_capture(
        let device_rate = config.sample_rate.0;
        let stream = match sample_format {
            SampleFormat::F32 => build_input::<f32, _>(
-                &device, &config, producer, channels, overrun.clone(), callbacks.clone(),
+                &device,
+                &config,
+                producer,
+                channels,
+                overrun.clone(),
+                callbacks.clone(),
                err_code.clone(),
            ),
            SampleFormat::I16 => build_input::<i16, _>(
-                &device, &config, producer, channels, overrun.clone(), callbacks.clone(),
+                &device,
+                &config,
+                producer,
+                channels,
+                overrun.clone(),
+                callbacks.clone(),
                err_code.clone(),
            ),
            SampleFormat::U16 => build_input::<u16, _>(
-                &device, &config, producer, channels, overrun.clone(), callbacks.clone(),
+                &device,
+                &config,
+                producer,
+                channels,
+                overrun.clone(),
+                callbacks.clone(),
                err_code.clone(),
            ),
            other => Err(AudioError::Stream(format!(
@@ -764,7 +781,10 @@ fn run_capture(
        // Surface a stream error the RT callback flagged (it can't log itself).
        let ec = err_code.load(Ordering::Relaxed);
        if ec != STREAM_ERR_NONE && ec != last_err {
-            crate::log_msg(&format!("cpal capture stream error: {}", stream_err_text(ec)));
+            crate::log_msg(&format!(
+                "cpal capture stream error: {}",
+                stream_err_text(ec)
+            ));
            last_err = ec;
        }
        if !drained {
@@ -914,16 +934,34 @@ fn run_playback(
        let device_rate = config.sample_rate.0;
        let stream = match sample_format {
            SampleFormat::F32 => build_output::<f32, _>(
-                &device, &config, consumer, ring_fill.clone(), underrun.clone(),
-                max_cb.clone(), callbacks.clone(), err_code.clone(),
+                &device,
+                &config,
+                consumer,
+                ring_fill.clone(),
+                underrun.clone(),
+                max_cb.clone(),
+                callbacks.clone(),
+                err_code.clone(),
            ),
            SampleFormat::I16 => build_output::<i16, _>(
-                &device, &config, consumer, ring_fill.clone(), underrun.clone(),
-                max_cb.clone(), callbacks.clone(), err_code.clone(),
+                &device,
+                &config,
+                consumer,
+                ring_fill.clone(),
+                underrun.clone(),
+                max_cb.clone(),
+                callbacks.clone(),
+                err_code.clone(),
            ),
            SampleFormat::U16 => build_output::<u16, _>(
-                &device, &config, consumer, ring_fill.clone(), underrun.clone(),
-                max_cb.clone(), callbacks.clone(), err_code.clone(),
+                &device,
+                &config,
+                consumer,
+                ring_fill.clone(),
+                underrun.clone(),
+                max_cb.clone(),
+                callbacks.clone(),
+                err_code.clone(),
            ),
            other => Err(AudioError::Stream(format!(
                "unsupported playback sample format: {other:?}"
@@ -1199,7 +1237,10 @@ fn spawn_health_logger(
            // Surface a stream error the RT callback flagged (it can't log itself).
            let ec = err_code.load(Ordering::Relaxed);
            if ec != STREAM_ERR_NONE && ec != last_err {
-                crate::log_msg(&format!("cpal playback stream error: {}", stream_err_text(ec)));
+                crate::log_msg(&format!(
+                    "cpal playback stream error: {}",
+                    stream_err_text(ec)
+                ));
                last_err = ec;
            }
            // Report the device's per-cycle demand (in internal 48 kHz-stereo
@@ -54,7 +54,10 @@ impl Drop for EchoCancelGuard {
            .arg("unload-module")
            .arg(&self.module_index)
            .output();
-        crate::log_msg(&format!("Echo cancel: unloaded module {}", self.module_index));
+        crate::log_msg(&format!(
+            "Echo cancel: unloaded module {}",
+            self.module_index
+        ));
    }
 }

@@ -65,7 +68,10 @@ impl Drop for EchoCancelGuard {
 /// `None` (or an empty string) to bind to the system defaults. Returns `Err` with
 /// a human-readable reason if `pactl` is missing, the load fails, or the nodes
 /// don't appear — the caller should fall back to the direct devices.
-pub fn enable(real_source: Option<&str>, real_sink: Option<&str>) -> Result<EchoCancelGuard, String> {
+pub fn enable(
+    real_source: Option<&str>,
+    real_sink: Option<&str>,
+) -> Result<EchoCancelGuard, String> {
    // Best-effort: clear any stale instance left by a crashed prior run so we
    // don't stack duplicate modules / fight over the virtual node names.
    unload_stale();
@@ -101,7 +107,11 @@ pub fn enable(real_source: Option<&str>, real_sink: Option<&str>) -> Result<Echo
    if module_index.parse::<u64>().is_err() {
        return Err(format!("unexpected pactl output: {module_index:?}"));
    }
-    let guard = EchoCancelGuard { module_index, source_name, sink_name };
+    let guard = EchoCancelGuard {
+        module_index,
+        source_name,
+        sink_name,
+    };

    // The virtual nodes appear shortly after the module loads; wait for both so
    // the subsequent capture/playback streams can actually target them. If they
@@ -134,7 +144,12 @@ fn wait_for_nodes(source_name: &str, sink_name: &str) -> bool {
 /// Whether `pactl list <kind> short` lists a node named `name`.
 /// `kind` is "sources" or "sinks".
 fn node_present(kind: &str, name: &str) -> bool {
-    let Ok(out) = Command::new("pactl").arg("list").arg(kind).arg("short").output() else {
+    let Ok(out) = Command::new("pactl")
+        .arg("list")
+        .arg(kind)
+        .arg("short")
+        .output()
+    else {
        return false;
    };
    String::from_utf8_lossy(&out.stdout)
@@ -167,7 +182,12 @@ fn process_is_alive(_pid: u32) -> bool {
 /// Unloads leftover PeerSpeak `module-echo-cancel` instances only when their
 /// owning process is gone. Best-effort and conservative on non-Linux platforms.
 fn unload_stale() {
-    let Ok(out) = Command::new("pactl").arg("list").arg("modules").arg("short").output() else {
+    let Ok(out) = Command::new("pactl")
+        .arg("list")
+        .arg("modules")
+        .arg("short")
+        .output()
+    else {
        return;
    };
    for line in String::from_utf8_lossy(&out.stdout).lines() {
@@ -179,7 +199,10 @@ fn unload_stale() {
            && ec_module_is_stale(args, process_is_alive)
            && index.parse::<u64>().is_ok()
        {
-            let _ = Command::new("pactl").arg("unload-module").arg(index).output();
+            let _ = Command::new("pactl")
+                .arg("unload-module")
+                .arg(index)
+                .output();
            crate::log_msg(&format!("Echo cancel: cleaned up stale module {index}"));
        }
    }
@@ -198,13 +221,25 @@ mod tests {
        let guard = enable(None, None).expect("module-echo-cancel should load");
        let source_name = guard.source_name().to_string();
        let sink_name = guard.sink_name().to_string();
-        assert!(node_present("sources", &source_name), "cleaned source must exist");
-        assert!(node_present("sinks", &sink_name), "reference sink must exist");
+        assert!(
+            node_present("sources", &source_name),
+            "cleaned source must exist"
+        );
+        assert!(
+            node_present("sinks", &sink_name),
+            "reference sink must exist"
+        );
        drop(guard);
        // Give pactl a moment to tear the nodes down.
        std::thread::sleep(Duration::from_millis(300));
-        assert!(!node_present("sources", &source_name), "source must be gone after unload");
-        assert!(!node_present("sinks", &sink_name), "sink must be gone after unload");
+        assert!(
+            !node_present("sources", &source_name),
+            "source must be gone after unload"
+        );
+        assert!(
+            !node_present("sinks", &sink_name),
+            "sink must be gone after unload"
+        );
    }

    #[test]
@@ -220,7 +255,10 @@ mod tests {
            pid_from_ec_args("source_name=peerspeak_echocancel_source.not-a-pid"),
            None
        );
-        assert_eq!(pid_from_ec_args("source_name=someone_elses_source.4242"), None);
+        assert_eq!(
+            pid_from_ec_args("source_name=someone_elses_source.4242"),
+            None
+        );
    }

    #[test]
@@ -251,7 +251,10 @@ mod tests {
        let before = rms(&low);
        eq.process_frame(&mut low);
        let after = rms(&low);
-        assert!(after > before * 1.6, "low shelf should boost low RMS: {before} -> {after}");
+        assert!(
+            after > before * 1.6,
+            "low shelf should boost low RMS: {before} -> {after}"
+        );
    }

    #[test]
@@ -264,7 +267,10 @@ mod tests {
        let before = rms(&high);
        eq.process_frame(&mut high);
        let after = rms(&high);
-        assert!(after > before * 1.6, "high shelf should boost high RMS: {before} -> {after}");
+        assert!(
+            after > before * 1.6,
+            "high shelf should boost high RMS: {before} -> {after}"
+        );
    }

    #[test]
@@ -275,7 +281,10 @@ mod tests {
                Biquad::peaking(DEFAULT_SAMPLE_RATE, MID_PEAK_HZ, gain, MID_Q),
                Biquad::high_shelf(DEFAULT_SAMPLE_RATE, HIGH_SHELF_HZ, gain, SHELF_Q),
            ] {
-                assert!(b.coeffs.all_finite(), "coefficients must be finite at {gain} dB");
+                assert!(
+                    b.coeffs.all_finite(),
+                    "coefficients must be finite at {gain} dB"
+                );
            }
        }
    }
@@ -289,12 +298,11 @@ mod tests {
        });
        let mut frame = sine(1_000.0, 48_000, 30_000.0);
        eq.process_frame(&mut frame);
-        let peak = frame
-            .iter()
-            .map(|&s| i32::from(s).abs())
-            .max()
-            .unwrap_or(0);
-        assert!(peak > 1_000, "processed signal should retain audible energy");
+        let peak = frame.iter().map(|&s| i32::from(s).abs()).max().unwrap_or(0);
+        assert!(
+            peak > 1_000,
+            "processed signal should retain audible energy"
+        );
        assert!(
            frame.iter().any(|&s| s > 0) && frame.iter().any(|&s| s < 0),
            "a boosted sine should retain both polarities"
@@ -169,7 +169,10 @@ mod tests {
            assert!(g.process(&mut f, 0.05), "loud frame must transmit");
            last = peak(&f);
        }
-        assert!(last >= 9900, "gain should reach ~1.0 on sustained loud input, got peak {last}");
+        assert!(
+            last >= 9900,
+            "gain should reach ~1.0 on sustained loud input, got peak {last}"
+        );
    }

    #[test]
@@ -179,8 +182,15 @@ mod tests {
        g.process(&mut f, 0.05);
        // 5ms attack @48k = 240 samples; across a 960-sample frame the gain ramps
        // 0->1, so the early samples are well below full scale (no instant click).
-        assert!(f[0].abs() < 5000, "attack should start near zero, got {}", f[0]);
-        assert!(f[FRAME - 1].abs() > 9000, "attack should complete within the frame");
+        assert!(
+            f[0].abs() < 5000,
+            "attack should start near zero, got {}",
+            f[0]
+        );
+        assert!(
+            f[FRAME - 1].abs() > 9000,
+            "attack should complete within the frame"
+        );
    }

    #[test]
@@ -193,8 +203,14 @@ mod tests {
        }
        // First quiet frame right after speech: hold keeps it open (not chopped).
        let mut q = frame(50); // rms ~0.0015, below close (0.03)
-        assert!(g.process(&mut q, 0.05), "first quiet frame must stay open (hangover)");
-        assert!(peak(&q) > 0, "held-open frame must not be silenced immediately");
+        assert!(
+            g.process(&mut q, 0.05),
+            "first quiet frame must stay open (hangover)"
+        );
+        assert!(
+            peak(&q) > 0,
+            "held-open frame must not be silenced immediately"
+        );

        // Hold is 200ms = 10 frames; keep feeding quiet until it fully closes.
        let mut closed = false;
@@ -205,7 +221,10 @@ mod tests {
                break;
            }
        }
-        assert!(closed, "gate must eventually close and stop transmitting after sustained silence");
+        assert!(
+            closed,
+            "gate must eventually close and stop transmitting after sustained silence"
+        );
    }

    #[test]
@@ -216,8 +235,14 @@ mod tests {
        g.process(&mut f, 0.05); // open=0.05, close=0.03
        // A frame between close and open thresholds: rms ~0.04 (amp ~1310).
        let mut mid = frame(1310);
-        assert!(g.process(&mut mid, 0.05), "between-threshold frame must keep an open gate open");
-        assert!(g.open, "hysteresis: gate stays open above the close threshold");
+        assert!(
+            g.process(&mut mid, 0.05),
+            "between-threshold frame must keep an open gate open"
+        );
+        assert!(
+            g.open,
+            "hysteresis: gate stays open above the close threshold"
+        );
    }

    #[test]
@@ -225,7 +250,10 @@ mod tests {
        let mut g = NoiseGate::new(SR);
        // Never opened; feed silence — should report don't-transmit promptly.
        let mut f = frame(0);
-        assert!(!g.process(&mut f, 0.05), "an unopened gate on silence must not transmit");
+        assert!(
+            !g.process(&mut f, 0.05),
+            "an unopened gate on silence must not transmit"
+        );
    }

    #[test]
@@ -266,7 +294,11 @@ mod tests {

        let mut f2 = frame(10000);
        assert!(g.process(&mut f2, 0.05)); // enabled
-        assert!(f2[0].abs() > 9000, "expected first sample of enabled frame to have no fade-in, got {}", f2[0]);
+        assert!(
+            f2[0].abs() > 9000,
+            "expected first sample of enabled frame to have no fade-in, got {}",
+            f2[0]
+        );
    }

    #[test]
@@ -302,7 +334,10 @@ mod tests {
            let mut f = frame(1310);
            assert!(g.process(&mut f, 0.05));
        }
-        assert!(g.open, "gate must stay open (hold refreshed by mid-level input)");
+        assert!(
+            g.open,
+            "gate must stay open (hold refreshed by mid-level input)"
+        );
    }

    #[test]
@@ -333,6 +368,10 @@ mod tests {
            last_peak = peak(&f);
        }
        assert!(g.open);
-        assert!(last_peak >= 9900, "peak of the 3rd reopened frame must be >= 9900, got {}", last_peak);
+        assert!(
+            last_peak >= 9900,
+            "peak of the 3rd reopened frame must be >= 9900, got {}",
+            last_peak
+        );
    }
 }
@@ -123,7 +123,10 @@ mod tests {
        let out = lim.process(&loud, 1.0);
        let ceiling = lim.ceiling().ceil() as i16;
        for &s in &out {
-            assert!(s > 0, "positive loud input stays positive (no wrap), got {s}");
+            assert!(
+                s > 0,
+                "positive loud input stays positive (no wrap), got {s}"
+            );
            assert!(s <= ceiling, "sample {s} exceeded ceiling {ceiling}");
        }
    }
@@ -175,7 +178,10 @@ mod tests {
        let out_pos = lim.process(&pos_loud, 1.0);
        for &s in &out_pos {
            assert!(s > 0, "positive input stays positive, got {s}");
-            assert!(s <= ceiling_ceil, "positive sample {s} exceeded ceiling {ceiling_ceil}");
+            assert!(
+                s <= ceiling_ceil,
+                "positive sample {s} exceeded ceiling {ceiling_ceil}"
+            );
        }

        // Sustained negative loud sum
@@ -185,7 +191,10 @@ mod tests {
        let neg_ceiling = -ceiling_ceil;
        for &s in &out_neg {
            assert!(s < 0, "negative input stays negative, got {s}");
-            assert!(s >= neg_ceiling, "negative sample {s} exceeded negative ceiling {neg_ceiling}");
+            assert!(
+                s >= neg_ceiling,
+                "negative sample {s} exceeded negative ceiling {neg_ceiling}"
+            );
        }
    }

@@ -200,8 +209,14 @@ mod tests {
        let out = lim.process(&input, 8.0);
        for &s in &out {
            assert!(s > 0, "positive stays positive");
-            assert!(s <= ceiling_ceil, "sample {s} must be limited to ceiling {ceiling_ceil}");
-            assert!((s - ceiling_ceil).abs() <= 2, "sample {s} should ride the ceiling {ceiling_ceil}");
+            assert!(
+                s <= ceiling_ceil,
+                "sample {s} must be limited to ceiling {ceiling_ceil}"
+            );
+            assert!(
+                (s - ceiling_ceil).abs() <= 2,
+                "sample {s} should ride the ceiling {ceiling_ceil}"
+            );
        }
    }

@@ -213,7 +228,10 @@ mod tests {
        let out = lim.process(&input, 0.5);
        for (i, &s) in out.iter().enumerate() {
            let expected = (input[i] as f32 * 0.5).round() as i16;
-            assert!((s - expected).abs() <= 1, "sample {s} should be close to expected {expected}");
+            assert!(
+                (s - expected).abs() <= 1,
+                "sample {s} should be close to expected {expected}"
+            );
        }

        // Subsequently feed a new sample at unity gain. It must be transparent,
@@ -230,7 +248,12 @@ mod tests {

        let loud = vec![200_000i32; 10];
        let out = lim.process(&loud, 1.0);
-        assert!(out[0] <= ceiling_ceil, "first sample {} must not overshoot ceiling {}", out[0], ceiling_ceil);
+        assert!(
+            out[0] <= ceiling_ceil,
+            "first sample {} must not overshoot ceiling {}",
+            out[0],
+            ceiling_ceil
+        );
    }

    /// 5. Release direction & monotonicity.
@@ -247,13 +270,23 @@ mod tests {

        // Output should be monotonic (non-decreasing)
        for i in 1..out.len() {
-            assert!(out[i] >= out[i - 1], "output must be monotonic; index {} was {}, index {} was {}", i - 1, out[i - 1], i, out[i]);
+            assert!(
+                out[i] >= out[i - 1],
+                "output must be monotonic; index {} was {}, index {} was {}",
+                i - 1,
+                out[i - 1],
+                i,
+                out[i]
+            );
        }

        // The end sample should be closer to the original input than the start sample
        let start_diff = (mid_val as i16 - out[0]).abs();
        let end_diff = (mid_val as i16 - *out.last().unwrap()).abs();
-        assert!(end_diff < start_diff, "end diff {end_diff} should be smaller than start diff {start_diff}");
+        assert!(
+            end_diff < start_diff,
+            "end diff {end_diff} should be smaller than start diff {start_diff}"
+        );
    }

    /// 6. Release is gradual, not instantaneous.
@@ -265,7 +298,11 @@ mod tests {

        // Immediately follow with a sub-ceiling sample
        let out = lim.process(&[10_000i32], 1.0);
-        assert!(out[0] < 10_000, "first quiet sample should still be attenuated (got {})", out[0]);
+        assert!(
+            out[0] < 10_000,
+            "first quiet sample should still be attenuated (got {})",
+            out[0]
+        );
    }

    /// 7. State carries across process calls.
@@ -287,7 +324,10 @@ mod tests {
        let mut out_split = out_split1;
        out_split.extend(&out_split2);

-        assert_eq!(out_single, out_split, "splitting process calls must produce identical output to a single call");
+        assert_eq!(
+            out_single, out_split,
+            "splitting process calls must produce identical output to a single call"
+        );

        // Test 2: Pre-loaded limiter vs fresh limiter on the same input
        let mut lim_preloaded = SoftLimiter::new(SR);
@@ -299,8 +339,16 @@ mod tests {
        let out_preloaded = lim_preloaded.process(&test_input, 1.0);
        let out_fresh = lim_fresh.process(&test_input, 1.0);

-        assert_ne!(out_preloaded, out_fresh, "pre-loaded and fresh limiter outputs should differ");
-        assert!(out_preloaded[0] < out_fresh[0], "pre-loaded limiter first sample {} should be smaller than fresh limiter first sample {}", out_preloaded[0], out_fresh[0]);
+        assert_ne!(
+            out_preloaded, out_fresh,
+            "pre-loaded and fresh limiter outputs should differ"
+        );
+        assert!(
+            out_preloaded[0] < out_fresh[0],
+            "pre-loaded limiter first sample {} should be smaller than fresh limiter first sample {}",
+            out_preloaded[0],
+            out_fresh[0]
+        );
    }

    /// 8. Empty input.
@@ -320,7 +368,10 @@ mod tests {
        // Gain 0.0
        let out_zero = lim.process(&input, 0.0);
        assert_eq!(out_zero.len(), input.len());
-        assert!(out_zero.iter().all(|&s| s == 0), "0.0 gain should result in all zeros");
+        assert!(
+            out_zero.iter().all(|&s| s == 0),
+            "0.0 gain should result in all zeros"
+        );

        // Gain 1.0
        let out_unity = lim.process(&input, 1.0);
@@ -354,6 +405,9 @@ mod tests {

        let out = lim.process(&input, 1.0);
        let expected: Vec<i16> = input.iter().map(|&s| s as i16).collect();
-        assert_eq!(out, expected, "below ceiling input must be bit-exact at unity gain");
+        assert_eq!(
+            out, expected,
+            "below ceiling input must be bit-exact at unity gain"
+        );
    }
 }
@@ -1,6 +1,6 @@
-use std::sync::mpsc::{Receiver, Sender};
 use std::sync::Arc;
 use std::sync::atomic::AtomicUsize;
+use std::sync::mpsc::{Receiver, Sender};
 use thiserror::Error;

 /// Playback output channel count. Capture/encode/network remain mono; only the
@@ -35,7 +35,11 @@ pub enum AudioError {
 pub trait AudioBackend: Send + Sync {
    /// Starts capturing raw PCM audio from the input device (microphone),
    /// sending chunks of samples (e.g. `Vec<i16>`) to the provided Sender.
-    fn start_capture(&self, tx: Sender<Vec<i16>>, target_node: Option<String>) -> Result<(), AudioError>;
+    fn start_capture(
+        &self,
+        tx: Sender<Vec<i16>>,
+        target_node: Option<String>,
+    ) -> Result<(), AudioError>;

    /// Starts playing back raw PCM audio to the output device (speaker),
    /// reading mixed/incoming chunks of samples from the provided Receiver.
@@ -65,16 +69,16 @@ pub mod pan;
 // Linear resamplers used by the Windows/cpal backend (W4). Platform-neutral and
 // pure, so it builds (and its tests run) everywhere even though only the cpal
 // backend wires it in.
-pub mod resample;
+#[cfg(windows)]
+pub mod cpal_impl;
 #[cfg(target_os = "linux")]
 pub mod echo_cancel;
 #[cfg(target_os = "linux")]
 pub mod pipewire_impl;
-#[cfg(windows)]
-pub mod cpal_impl;
 #[cfg(target_os = "linux")]
 pub mod pw_cli;
 pub mod recorder;
+pub mod resample;

 /// A selectable audio device for the input/output pickers. `name` is the stable
 /// identifier the backend uses to request the device (`target_node`);
@@ -96,10 +100,10 @@ impl std::fmt::Display for AudioDevice {
 // Enumerate audio input/output devices for the pickers (sorted by description),
 // returning the same `AudioDevice` shape regardless of platform: PipeWire
 // (`pw-cli`) on Linux, cpal/WASAPI on Windows.
-#[cfg(target_os = "linux")]
-pub use pw_cli::enumerate_audio_devices;
 #[cfg(windows)]
 pub use cpal_impl::enumerate_audio_devices;
+#[cfg(target_os = "linux")]
+pub use pw_cli::enumerate_audio_devices;

 /// The audio backend implementation for the current platform.
 ///
@@ -12,9 +12,11 @@
 //! This module is pure plumbing over [`WavWriter`]: no audio decode, no
 //! networking, no realtime work. The mixer (a non-RT task) drives it.

-use std::collections::{HashMap, VecDeque};
+use std::collections::{HashMap, HashSet, VecDeque};
 use std::io;
 use std::path::{Path, PathBuf};
+use std::sync::mpsc::{self, SyncSender, TrySendError};
+use std::thread::{self, JoinHandle};

 use iroh::EndpointId;

@@ -24,6 +26,8 @@ use crate::core::jitter::FRAME_SAMPLES;
 /// Cap on the silence chunk written at once when pre-padding a late joiner, so a
 /// long-running call can't trigger a single multi-hundred-MB allocation.
 const SILENCE_CHUNK: usize = FRAME_SAMPLES * 256;
+const WRITER_QUEUE_CYCLES: usize = 256;
+const DROP_LOG_INTERVAL_CYCLES: u64 = 256;

 /// Cap on buffered mic samples (~200ms @ 48kHz). Bounds how far the mic track
 /// can drift if the capture clock runs ahead of the mixer cycle; past it the
@@ -56,41 +60,6 @@ pub fn create_session_dir(base: &Path, now_unix_secs: u64) -> io::Result<PathBuf
    ))
 }

-/// One output track: its WAV writer plus whether it has been written *this*
-/// cycle (so `end_cycle` knows which tracks to pad with silence).
-struct Track {
-    writer: WavWriter,
-    written_this_cycle: bool,
-}
-
-impl Track {
-    fn create(path: &Path) -> io::Result<Self> {
-        Ok(Self {
-            writer: WavWriter::new(path)?,
-            written_this_cycle: false,
-        })
-    }
-
-    /// Append `frame` fitted to exactly `frame_samples` (zero-padded if short),
-    /// and mark the track as written for this cycle.
-    fn write_frame(&mut self, frame: &[i16], frame_samples: usize) -> io::Result<()> {
-        self.writer.write_samples(&fit(frame, frame_samples))?;
-        self.written_this_cycle = true;
-        Ok(())
-    }
-
-    /// Append `samples` of silence (no cycle-marking — used for padding).
-    fn write_silence(&mut self, samples: usize) -> io::Result<()> {
-        let mut remaining = samples;
-        while remaining > 0 {
-            let n = remaining.min(SILENCE_CHUNK);
-            self.writer.write_samples(&vec![0i16; n])?;
-            remaining -= n;
-        }
-        Ok(())
-    }
-}
-
 /// Return `frame` resized to exactly `n` samples: truncated if longer (shouldn't
 /// happen — Opus frames are uniform), zero-padded if shorter.
 fn fit(frame: &[i16], n: usize) -> Vec<i16> {
@@ -108,7 +77,13 @@ pub fn track_filename(name: &str, id: &EndpointId) -> String {
    let clean = crate::sanitize::sanitize_name(name);
    let mut slug: String = clean
        .chars()
-        .map(|c| if c.is_ascii_alphanumeric() { c.to_ascii_lowercase() } else { '-' })
+        .map(|c| {
+            if c.is_ascii_alphanumeric() {
+                c.to_ascii_lowercase()
+            } else {
+                '-'
+            }
+        })
        .collect();
    // Collapse runs of '-' and trim them off the ends.
    while slug.contains("--") {
@@ -120,41 +95,210 @@ pub fn track_filename(name: &str, id: &EndpointId) -> String {
    format!("{slug}-{short}.wav")
 }

-/// A live multitrack recording: per-peer stems + your mic, plus an optional
-/// mixed track, all under one session directory and clocked together.
-pub struct MultitrackRecorder {
-    dir: PathBuf,
-    frame_samples: usize,
-    /// Cycles recorded so far = the shared length (in frames) of every track.
-    cycles: u64,
-    peers: HashMap<EndpointId, Track>,
-    /// Your mic track. Fed asynchronously from the capture thread via
-    /// [`push_mic`](MultitrackRecorder::push_mic) into `mic_fifo`, then drained
-    /// one frame per `end_cycle` so it aligns with the cycle clock.
-    mic: WavWriter,
-    mic_fifo: VecDeque<i16>,
-    /// Present in "Both" mode (stems + mixed), absent in "stems only".
-    mix: Option<Track>,
+#[derive(Default)]
+struct PendingCycle {
+    new_peers: Vec<NewPeer>,
+    peer_frames: HashMap<EndpointId, Vec<i16>>,
+    mix_frame: Option<Vec<i16>>,
 }

-impl MultitrackRecorder {
-    /// Create a recording in `dir` (which must already exist). `with_mix` adds
-    /// the convenience mixed track (`mix.wav`). Your mic is always `me.wav`.
-    pub fn create(dir: &Path, frame_samples: usize, with_mix: bool) -> io::Result<Self> {
+struct NewPeer {
+    id: EndpointId,
+    filename: String,
+}
+
+struct CycleBatch {
+    new_peers: Vec<NewPeer>,
+    mic_frame: Vec<i16>,
+    mix_frame: Option<Vec<i16>>,
+    peer_frames: HashMap<EndpointId, Vec<i16>>,
+}
+
+trait SampleWriter {
+    fn write_samples(&mut self, samples: &[i16]) -> io::Result<()>;
+    fn finalize(self) -> io::Result<()>;
+}
+
+impl SampleWriter for WavWriter {
+    fn write_samples(&mut self, samples: &[i16]) -> io::Result<()> {
+        WavWriter::write_samples(self, samples)
+    }
+
+    fn finalize(self) -> io::Result<()> {
+        WavWriter::finalize(self)
+    }
+}
+
+struct WriterState<W> {
+    dir: PathBuf,
+    frame_samples: usize,
+    peers: HashMap<EndpointId, W>,
+    mic: W,
+    mix: Option<W>,
+    cycles_written: u64,
+}
+
+impl WriterState<WavWriter> {
+    fn create(dir: &Path, frame_samples: usize, with_mix: bool) -> io::Result<Self> {
        let mic = WavWriter::new(&dir.join("me.wav"))?;
        let mix = if with_mix {
-            Some(Track::create(&dir.join("mix.wav"))?)
+            Some(WavWriter::new(&dir.join("mix.wav"))?)
        } else {
            None
        };
        Ok(Self {
            dir: dir.to_path_buf(),
            frame_samples,
-            cycles: 0,
            peers: HashMap::new(),
            mic,
-            mic_fifo: VecDeque::new(),
            mix,
+            cycles_written: 0,
+        })
+    }
+}
+
+impl<W: SampleWriter> WriterState<W> {
+    fn apply_batch<F>(&mut self, batch: &CycleBatch, mut create_peer: F) -> io::Result<()>
+    where
+        F: FnMut(&Path) -> io::Result<W>,
+    {
+        for peer in &batch.new_peers {
+            if !self.peers.contains_key(&peer.id) {
+                let writer = create_peer(&self.dir.join(&peer.filename))?;
+                self.peers.insert(peer.id, writer);
+                let pad = self.back_pad_samples()?;
+                let writer = self.peers.get_mut(&peer.id).unwrap();
+                Self::write_silence(writer, pad)?;
+            }
+        }
+
+        self.mic.write_samples(&batch.mic_frame)?;
+        if let Some(mix) = self.mix.as_mut() {
+            if let Some(frame) = batch.mix_frame.as_deref() {
+                mix.write_samples(frame)?;
+            } else {
+                Self::write_silence(mix, self.frame_samples)?;
+            }
+        }
+
+        let silence = vec![0i16; self.frame_samples];
+        for (id, writer) in &mut self.peers {
+            let frame = batch
+                .peer_frames
+                .get(id)
+                .map(Vec::as_slice)
+                .unwrap_or(&silence);
+            writer.write_samples(frame)?;
+        }
+        self.cycles_written += 1;
+        Ok(())
+    }
+
+    fn back_pad_samples(&self) -> io::Result<usize> {
+        let cycles = usize::try_from(self.cycles_written)
+            .map_err(|_| io::Error::other("multitrack recording too long"))?;
+        cycles
+            .checked_mul(self.frame_samples)
+            .ok_or_else(|| io::Error::other("multitrack recording too long"))
+    }
+
+    fn write_silence(writer: &mut W, samples: usize) -> io::Result<()> {
+        let mut remaining = samples;
+        let silence = vec![0i16; remaining.min(SILENCE_CHUNK)];
+        while remaining > 0 {
+            let n = remaining.min(silence.len());
+            writer.write_samples(&silence[..n])?;
+            remaining -= n;
+        }
+        Ok(())
+    }
+
+    fn finalize(self) -> io::Result<()> {
+        let mut first_finalize_error = None;
+        record_first_error(&mut first_finalize_error, self.mic.finalize());
+        if let Some(mix) = self.mix {
+            record_first_error(&mut first_finalize_error, mix.finalize());
+        }
+        for writer in self.peers.into_values() {
+            record_first_error(&mut first_finalize_error, writer.finalize());
+        }
+        if let Some(e) = first_finalize_error {
+            Err(e)
+        } else {
+            Ok(())
+        }
+    }
+}
+
+fn record_first_error(slot: &mut Option<io::Error>, result: io::Result<()>) {
+    if slot.is_none()
+        && let Err(e) = result
+    {
+        *slot = Some(e);
+    }
+}
+
+/// Applies whole-cycle batches on the writer thread. Each applied batch appends
+/// exactly `frame_samples` to every existing track, and a dropped batch never
+/// reaches this loop for any track, so stem lengths stay equal even when the
+/// bounded queue applies back-pressure.
+fn writer_thread_main(
+    mut state: WriterState<WavWriter>,
+    batch_rx: mpsc::Receiver<CycleBatch>,
+) -> io::Result<()> {
+    let mut first_write_error = None;
+
+    for batch in batch_rx {
+        if first_write_error.is_none()
+            && let Err(e) = state.apply_batch(&batch, WavWriter::new)
+        {
+            first_write_error = Some(e);
+        }
+    }
+
+    let finalize_result = state.finalize();
+    if let Some(e) = first_write_error {
+        Err(e)
+    } else {
+        finalize_result
+    }
+}
+
+/// A live multitrack recording: per-peer stems + your mic, plus an optional
+/// mixed track, all under one session directory and clocked together.
+pub struct MultitrackRecorder {
+    dir: PathBuf,
+    frame_samples: usize,
+    known_peers: HashSet<EndpointId>,
+    /// Your mic track. Fed asynchronously from the capture thread via
+    /// [`push_mic`](MultitrackRecorder::push_mic) into `mic_fifo`, then drained
+    /// one frame per `end_cycle` so it aligns with the cycle clock.
+    mic_fifo: VecDeque<i16>,
+    /// Present in "Both" mode (stems + mixed), absent in "stems only".
+    with_mix: bool,
+    batch_tx: SyncSender<CycleBatch>,
+    writer_thread: JoinHandle<io::Result<()>>,
+    dropped_cycles: u64,
+    pending: PendingCycle,
+}
+
+impl MultitrackRecorder {
+    /// Create a recording in `dir` (which must already exist). `with_mix` adds
+    /// the convenience mixed track (`mix.wav`). Your mic is always `me.wav`.
+    pub fn create(dir: &Path, frame_samples: usize, with_mix: bool) -> io::Result<Self> {
+        let writer_state = WriterState::create(dir, frame_samples, with_mix)?;
+        let (batch_tx, batch_rx) = mpsc::sync_channel(WRITER_QUEUE_CYCLES);
+        let writer_thread = thread::spawn(move || writer_thread_main(writer_state, batch_rx));
+        Ok(Self {
+            dir: dir.to_path_buf(),
+            frame_samples,
+            known_peers: HashSet::new(),
+            mic_fifo: VecDeque::new(),
+            with_mix,
+            batch_tx,
+            writer_thread,
+            dropped_cycles: 0,
+            pending: PendingCycle::default(),
        })
    }

@@ -167,12 +311,14 @@ impl MultitrackRecorder {
    /// so it aligns with the others. Idempotent: a peer already tracked is left
    /// as-is (re-announce / name change doesn't restart their file).
    pub fn add_peer(&mut self, id: EndpointId, name: &str) -> io::Result<()> {
-        if self.peers.contains_key(&id) {
+        if self.known_peers.contains(&id) {
            return Ok(());
        }
-        let mut track = Track::create(&self.dir.join(track_filename(name, &id)))?;
-        track.write_silence(self.cycles as usize * self.frame_samples)?;
-        self.peers.insert(id, track);
+        self.known_peers.insert(id);
+        self.pending.new_peers.push(NewPeer {
+            id,
+            filename: track_filename(name, &id),
+        });
        Ok(())
    }

@@ -180,11 +326,13 @@ impl MultitrackRecorder {
    /// registered yet (write raced ahead of the join event), auto-register it
    /// with an id-only name so no audio is dropped.
    pub fn write_peer(&mut self, id: EndpointId, frame: &[i16]) -> io::Result<()> {
-        if !self.peers.contains_key(&id) {
+        if !self.known_peers.contains(&id) {
            self.add_peer(id, "")?;
        }
-        let fs = self.frame_samples;
-        self.peers.get_mut(&id).unwrap().write_frame(frame, fs)
+        self.pending
+            .peer_frames
+            .insert(id, fit(frame, self.frame_samples));
+        Ok(())
    }

    /// Buffer a frame of your transmitted mic audio (called from the capture
@@ -209,9 +357,8 @@ impl MultitrackRecorder {
    /// Record the finished mixed-bus frame for the current cycle (no-op in
    /// stems-only mode).
    pub fn write_mix(&mut self, frame: &[i16]) -> io::Result<()> {
-        let fs = self.frame_samples;
-        if let Some(mix) = self.mix.as_mut() {
-            mix.write_frame(frame, fs)?;
+        if self.with_mix {
+            self.pending.mix_frame = Some(fit(frame, self.frame_samples));
        }
        Ok(())
    }
@@ -224,28 +371,63 @@ impl MultitrackRecorder {
        // Mic: always one frame per cycle, drained from the FIFO (silence on
        // underrun), so it tracks the cycle clock like the peer stems.
        let mic_frame = self.drain_mic(fs);
-        self.mic.write_samples(&mic_frame)?;
-        // Peers + the optional mix track: pad any not written this cycle.
-        for track in self.peers.values_mut().chain(self.mix.as_mut()) {
-            if !track.written_this_cycle {
-                track.write_silence(fs)?;
+        let mut pending = std::mem::take(&mut self.pending);
+        pending.new_peers.sort_by(|a, b| {
+            a.filename
+                .cmp(&b.filename)
+                .then_with(|| a.id.to_string().cmp(&b.id.to_string()))
+        });
+        let batch = CycleBatch {
+            new_peers: pending.new_peers,
+            mic_frame,
+            mix_frame: if self.with_mix {
+                pending.mix_frame
+            } else {
+                None
+            },
+            peer_frames: pending.peer_frames,
+        };
+        match self.batch_tx.try_send(batch) {
+            Ok(()) => Ok(()),
+            Err(TrySendError::Full(batch)) => {
+                for peer in &batch.new_peers {
+                    self.known_peers.remove(&peer.id);
+                }
+                self.dropped_cycles = self.dropped_cycles.saturating_add(1);
+                if self.dropped_cycles == 1
+                    || self.dropped_cycles.is_multiple_of(DROP_LOG_INTERVAL_CYCLES)
+                {
+                    crate::log_msg(&format!(
+                        "multitrack recording: writer queue full; dropped {} cycle(s)",
+                        self.dropped_cycles
+                    ));
+                }
+                Ok(())
            }
-            track.written_this_cycle = false;
+            Err(TrySendError::Disconnected(_)) => Err(io::Error::new(
+                io::ErrorKind::BrokenPipe,
+                "multitrack writer thread stopped",
+            )),
        }
-        self.cycles += 1;
-        Ok(())
    }

    /// Finalize every track's WAV header. Consumes the recorder.
    pub fn finalize(self) -> io::Result<()> {
-        self.mic.finalize()?;
-        if let Some(mix) = self.mix {
-            mix.writer.finalize()?;
-        }
-        for (_, track) in self.peers {
-            track.writer.finalize()?;
-        }
-        Ok(())
+        let Self {
+            dir: _,
+            frame_samples: _,
+            known_peers: _,
+            mic_fifo: _,
+            with_mix: _,
+            batch_tx,
+            writer_thread,
+            dropped_cycles: _,
+            pending: _,
+        } = self;
+        drop(batch_tx);
+        writer_thread
+            .join()
+            .unwrap_or_else(|_| Err(io::Error::other("multitrack writer thread panicked")))
    }
 }

@@ -271,6 +453,51 @@ mod tests {
        d
    }

+    #[derive(Default)]
+    struct TestWriter {
+        samples: Vec<i16>,
+    }
+
+    impl SampleWriter for TestWriter {
+        fn write_samples(&mut self, samples: &[i16]) -> io::Result<()> {
+            self.samples.extend_from_slice(samples);
+            Ok(())
+        }
+
+        fn finalize(self) -> io::Result<()> {
+            Ok(())
+        }
+    }
+
+    fn test_writer_state(frame_samples: usize, with_mix: bool) -> WriterState<TestWriter> {
+        WriterState {
+            dir: PathBuf::new(),
+            frame_samples,
+            peers: HashMap::new(),
+            mic: TestWriter::default(),
+            mix: if with_mix {
+                Some(TestWriter::default())
+            } else {
+                None
+            },
+            cycles_written: 0,
+        }
+    }
+
+    fn test_batch(
+        new_peers: Vec<NewPeer>,
+        mic_frame: Vec<i16>,
+        mix_frame: Option<Vec<i16>>,
+        peer_frames: Vec<(EndpointId, Vec<i16>)>,
+    ) -> CycleBatch {
+        CycleBatch {
+            new_peers,
+            mic_frame,
+            mix_frame,
+            peer_frames: peer_frames.into_iter().collect(),
+        }
+    }
+
    #[test]
    fn fit_pads_and_truncates() {
        assert_eq!(fit(&[1, 2], 4), vec![1, 2, 0, 0]);
@@ -284,7 +511,10 @@ mod tests {
        let short: String = id.to_string().chars().take(8).collect();
        assert_eq!(track_filename("Alice", &id), format!("alice-{short}.wav"));
        // Spaces / punctuation collapse to single dashes, trimmed.
-        assert_eq!(track_filename("  Bob the Builder! ", &id), format!("bob-the-builder-{short}.wav"));
+        assert_eq!(
+            track_filename("  Bob the Builder! ", &id),
+            format!("bob-the-builder-{short}.wav")
+        );
        // A name that sanitizes/slugs to nothing falls back to "peer".
        assert_eq!(track_filename("!!!", &id), format!("peer-{short}.wav"));
    }
@@ -302,6 +532,110 @@ mod tests {
        let _ = std::fs::remove_dir_all(&base);
    }

+    #[test]
+    fn apply_batch_advances_existing_tracks_and_back_pads_late_peer() {
+        let frame = 3;
+        let early = an_id();
+        let late = an_id();
+        let mut state = test_writer_state(frame, true);
+        state.cycles_written = 2;
+        state.mic.samples = vec![8; 2 * frame];
+        state.mix.as_mut().unwrap().samples = vec![6; 2 * frame];
+        state.peers.insert(
+            early,
+            TestWriter {
+                samples: vec![1; 2 * frame],
+            },
+        );
+
+        let batch = test_batch(
+            vec![NewPeer {
+                id: late,
+                filename: "late.wav".to_string(),
+            }],
+            vec![9; frame],
+            None,
+            vec![(early, vec![2; frame]), (late, vec![7; frame])],
+        );
+        state
+            .apply_batch(&batch, |_| Ok(TestWriter::default()))
+            .unwrap();
+
+        assert_eq!(state.cycles_written, 3);
+        assert_eq!(state.mic.samples.len(), 3 * frame);
+        assert_eq!(state.mix.as_ref().unwrap().samples.len(), 3 * frame);
+        assert_eq!(
+            &state.mix.as_ref().unwrap().samples[2 * frame..],
+            &[0, 0, 0]
+        );
+        assert_eq!(state.peers.get(&early).unwrap().samples.len(), 3 * frame);
+        assert_eq!(
+            &state.peers.get(&early).unwrap().samples[2 * frame..],
+            &[2, 2, 2]
+        );
+        assert_eq!(
+            state.peers.get(&late).unwrap().samples,
+            vec![0, 0, 0, 0, 0, 0, 7, 7, 7],
+            "late peer is back-padded by completed cycles before this batch"
+        );
+    }
+
+    #[test]
+    fn skipped_batches_keep_all_tracks_equal_length() {
+        let frame = 2;
+        let p1 = an_id();
+        let p2 = an_id();
+        let mut state = test_writer_state(frame, true);
+
+        let first = test_batch(
+            vec![
+                NewPeer {
+                    id: p1,
+                    filename: "p1.wav".to_string(),
+                },
+                NewPeer {
+                    id: p2,
+                    filename: "p2.wav".to_string(),
+                },
+            ],
+            vec![1; frame],
+            Some(vec![5; frame]),
+            vec![(p1, vec![10; frame]), (p2, vec![20; frame])],
+        );
+        state
+            .apply_batch(&first, |_| Ok(TestWriter::default()))
+            .unwrap();
+
+        let _dropped_cycle = test_batch(
+            Vec::new(),
+            vec![2; frame],
+            Some(vec![6; frame]),
+            vec![(p1, vec![11; frame])],
+        );
+
+        let after_drop = test_batch(
+            Vec::new(),
+            vec![3; frame],
+            None,
+            vec![(p1, vec![12; frame])],
+        );
+        state
+            .apply_batch(&after_drop, |_| Ok(TestWriter::default()))
+            .unwrap();
+
+        let expected = 2 * frame;
+        assert_eq!(state.cycles_written, 2);
+        assert_eq!(state.mic.samples.len(), expected);
+        assert_eq!(state.mix.as_ref().unwrap().samples.len(), expected);
+        assert_eq!(state.peers.get(&p1).unwrap().samples.len(), expected);
+        assert_eq!(state.peers.get(&p2).unwrap().samples.len(), expected);
+        assert_eq!(
+            &state.peers.get(&p2).unwrap().samples[frame..],
+            &[0, 0],
+            "peer absent from an applied batch gets silence for that cycle"
+        );
+    }
+
    #[test]
    fn all_tracks_equal_length_after_n_cycles() {
        let dir = tmpdir("equal");
@@ -327,10 +661,18 @@ mod tests {
        rec.finalize().unwrap();

        let expected = 3 * frame;
-        assert_eq!(wav_samples(&dir.join("me.wav")), expected, "mic padded to full length");
+        assert_eq!(
+            wav_samples(&dir.join("me.wav")),
+            expected,
+            "mic padded to full length"
+        );
        assert_eq!(wav_samples(&dir.join("mix.wav")), expected);
        assert_eq!(wav_samples(&dir.join(track_filename("p1", &p1))), expected);
-        assert_eq!(wav_samples(&dir.join(track_filename("p2", &p2))), expected, "silent peer still full length");
+        assert_eq!(
+            wav_samples(&dir.join(track_filename("p2", &p2))),
+            expected,
+            "silent peer still full length"
+        );
    }

    #[test]
@@ -357,8 +699,14 @@ mod tests {
        rec.finalize().unwrap();

        // Both tracks are the full 5 cycles long (late one was back-padded).
-        assert_eq!(wav_samples(&dir.join(track_filename("early", &early))), 5 * frame);
-        assert_eq!(wav_samples(&dir.join(track_filename("late", &late))), 5 * frame);
+        assert_eq!(
+            wav_samples(&dir.join(track_filename("early", &early))),
+            5 * frame
+        );
+        assert_eq!(
+            wav_samples(&dir.join(track_filename("late", &late))),
+            5 * frame
+        );

        // The late track's first 2 cycles are silence, then the real audio.
        let bytes = std::fs::read(dir.join(track_filename("late", &late))).unwrap();
@@ -378,6 +726,28 @@ mod tests {
        rec.end_cycle().unwrap();
        rec.finalize().unwrap();
        assert!(dir.join("me.wav").exists());
-        assert!(!dir.join("mix.wav").exists(), "no mix track in stems-only mode");
+        assert!(
+            !dir.join("mix.wav").exists(),
+            "no mix track in stems-only mode"
+        );
+    }
+
+    #[cfg(unix)]
+    #[test]
+    fn async_peer_create_error_surfaces_at_finalize() {
+        use std::os::unix::fs::PermissionsExt;
+
+        let dir = tmpdir("asyncerr");
+        let mut rec = MultitrackRecorder::create(&dir, 4, false).unwrap();
+        std::fs::set_permissions(&dir, std::fs::Permissions::from_mode(0o500)).unwrap();
+
+        rec.add_peer(an_id(), "blocked").unwrap();
+        rec.end_cycle().unwrap();
+        let result = rec.finalize();
+
+        std::fs::set_permissions(&dir, std::fs::Permissions::from_mode(0o700)).unwrap();
+        let err = result.unwrap_err();
+        assert_eq!(err.kind(), io::ErrorKind::PermissionDenied);
+        let _ = std::fs::remove_dir_all(&dir);
    }
 }
@@ -23,7 +23,10 @@ pub fn pan_gains(pan: f32) -> (f32, f32) {
 /// still following the same equal-power curve as a peer is moved away from center.
 pub fn playback_pan_gains(pan: f32) -> (f32, f32) {
    let (left, right) = pan_gains(pan);
-    (left * std::f32::consts::SQRT_2, right * std::f32::consts::SQRT_2)
+    (
+        left * std::f32::consts::SQRT_2,
+        right * std::f32::consts::SQRT_2,
+    )
 }

 #[cfg(test)]
@@ -36,8 +39,14 @@ mod tests {
    fn hard_left_and_right_are_endpoints() {
        assert_eq!(pan_gains(-1.0), (1.0, 0.0));
        let (l, r) = pan_gains(1.0);
-        assert!(l.abs() < EPS, "left at hard-right should be zero-ish, got {l}");
-        assert!((r - 1.0).abs() < EPS, "right at hard-right should be one, got {r}");
+        assert!(
+            l.abs() < EPS,
+            "left at hard-right should be zero-ish, got {l}"
+        );
+        assert!(
+            (r - 1.0).abs() < EPS,
+            "right at hard-right should be one, got {r}"
+        );
    }

    #[test]
@@ -55,8 +64,14 @@ mod tests {
        let mut prev_r = f32::NEG_INFINITY;
        for pan in pans {
            let (l, r) = pan_gains(pan);
-            assert!(l <= prev_l + EPS, "left gain must not rise as pan moves right");
-            assert!(r >= prev_r - EPS, "right gain must not fall as pan moves right");
+            assert!(
+                l <= prev_l + EPS,
+                "left gain must not rise as pan moves right"
+            );
+            assert!(
+                r >= prev_r - EPS,
+                "right gain must not fall as pan moves right"
+            );
            prev_l = l;
            prev_r = r;
        }
@@ -1,13 +1,16 @@
 use crate::audio::{AudioBackend, AudioError};
-use std::sync::mpsc::{Sender, Receiver, RecvTimeoutError};
-use std::sync::{Arc, Mutex};
-use std::sync::atomic::{AtomicBool, AtomicU64, AtomicUsize, Ordering};
-use std::thread::{self, JoinHandle};
-use std::time::Duration;
 use pipewire as pw;
 use pw::{properties::properties, spa};
+use ringbuf::{
+    HeapRb,
+    traits::{Consumer, Producer, Split},
+};
 use spa::pod::Pod;
-use ringbuf::{HeapRb, traits::{Consumer, Producer, Split}};
+use std::sync::atomic::{AtomicBool, AtomicU64, AtomicUsize, Ordering};
+use std::sync::mpsc::{Receiver, RecvTimeoutError, Sender};
+use std::sync::{Arc, Mutex};
+use std::thread::{self, JoinHandle};
+use std::time::Duration;

 pub struct PipeWireBackend {
    capture_state: Mutex<Option<CaptureState>>,
@@ -41,7 +44,11 @@ impl PipeWireBackend {
 }

 impl AudioBackend for PipeWireBackend {
-    fn start_capture(&self, tx: Sender<Vec<i16>>, target_node: Option<String>) -> Result<(), AudioError> {
+    fn start_capture(
+        &self,
+        tx: Sender<Vec<i16>>,
+        target_node: Option<String>,
+    ) -> Result<(), AudioError> {
        let mut capture_guard = self.capture_state.lock().unwrap();
        if capture_guard.is_some() {
            return Err(AudioError::Stream("Capture already started".to_string()));
@@ -108,12 +115,17 @@ impl AudioBackend for PipeWireBackend {
    }
 }

-fn run_capture(cmd_rx: pw::channel::Receiver<()>, tx: Sender<Vec<i16>>, target_node: Option<String>) -> Result<(), AudioError> {
-    let mainloop = pw::main_loop::MainLoopRc::new(None)
-        .map_err(|e| AudioError::Init(e.to_string()))?;
+fn run_capture(
+    cmd_rx: pw::channel::Receiver<()>,
+    tx: Sender<Vec<i16>>,
+    target_node: Option<String>,
+) -> Result<(), AudioError> {
+    let mainloop =
+        pw::main_loop::MainLoopRc::new(None).map_err(|e| AudioError::Init(e.to_string()))?;
    let context = pw::context::ContextRc::new(&mainloop, None)
        .map_err(|e| AudioError::Init(e.to_string()))?;
-    let core = context.connect_rc(None)
+    let core = context
+        .connect_rc(None)
        .map_err(|e| AudioError::Init(e.to_string()))?;

    // Ring buffer setup: 9600 samples (200ms capacity for mono 48kHz)
@@ -181,15 +193,16 @@ fn run_capture(cmd_rx: pw::channel::Receiver<()>, tx: Sender<Vec<i16>>, target_n

    let mut params = [Pod::from_bytes(&values).unwrap()];

-    stream.connect(
-        spa::utils::Direction::Input,
-        None,
-        pw::stream::StreamFlags::AUTOCONNECT
-            | pw::stream::StreamFlags::MAP_BUFFERS
-            | pw::stream::StreamFlags::RT_PROCESS,
-        &mut params,
-    )
-    .map_err(|e| AudioError::Stream(e.to_string()))?;
+    stream
+        .connect(
+            spa::utils::Direction::Input,
+            None,
+            pw::stream::StreamFlags::AUTOCONNECT
+                | pw::stream::StreamFlags::MAP_BUFFERS
+                | pw::stream::StreamFlags::RT_PROCESS,
+            &mut params,
+        )
+        .map_err(|e| AudioError::Stream(e.to_string()))?;

    // Spawn the worker thread to pop from consumer and send Vec<i16> frames
    let running = Arc::new(AtomicBool::new(true));
@@ -257,11 +270,7 @@ const WORKER_POLL: Duration = Duration::from_millis(100);
 /// every `WORKER_POLL` even when no frames arrive — this is what lets `stop()`
 /// join the worker promptly instead of hanging on a parked blocking `recv()`
 /// (bug A7). Pure w.r.t. its inputs (no PipeWire), so it's unit-testable.
-fn drain_loop(
-    rx: &Receiver<Vec<i16>>,
-    running: &AtomicBool,
-    mut on_frame: impl FnMut(Vec<i16>),
-) {
+fn drain_loop(rx: &Receiver<Vec<i16>>, running: &AtomicBool, mut on_frame: impl FnMut(Vec<i16>)) {
    while running.load(Ordering::Relaxed) {
        match rx.recv_timeout(WORKER_POLL) {
            Ok(frame) => on_frame(frame),
@@ -293,7 +302,11 @@ fn publish_frame<P: Producer<Item = i16>>(
 fn frames_to_produce(requested: usize, mapped_frames: usize) -> usize {
    /// Safe per-cycle fallback when the graph doesn't report a quantum.
    const FALLBACK_FRAMES: usize = 1024;
-    let want = if requested > 0 { requested } else { FALLBACK_FRAMES };
+    let want = if requested > 0 {
+        requested
+    } else {
+        FALLBACK_FRAMES
+    };
    want.min(mapped_frames)
 }

@@ -303,11 +316,12 @@ fn run_playback(
    target_node: Option<String>,
    fill_gauge: Arc<AtomicUsize>,
 ) -> Result<(), AudioError> {
-    let mainloop = pw::main_loop::MainLoopRc::new(None)
-        .map_err(|e| AudioError::Init(e.to_string()))?;
+    let mainloop =
+        pw::main_loop::MainLoopRc::new(None).map_err(|e| AudioError::Init(e.to_string()))?;
    let context = pw::context::ContextRc::new(&mainloop, None)
        .map_err(|e| AudioError::Init(e.to_string()))?;
-    let core = context.connect_rc(None)
+    let core = context
+        .connect_rc(None)
        .map_err(|e| AudioError::Init(e.to_string()))?;

    // Ring buffer setup: 19200 interleaved samples (200ms capacity for stereo
@@ -428,7 +442,9 @@ fn run_playback(
                        }
                        if starved > 0 {
                            // One wait-free atomic add per quantum — RT-safe.
-                            user_data.underrun_samples.fetch_add(starved, Ordering::Relaxed);
+                            user_data
+                                .underrun_samples
+                                .fetch_add(starved, Ordering::Relaxed);
                        }
                        // Decrement the exact occupancy counter by the samples we
                        // actually pulled (excluding underruns, which removed
@@ -493,7 +509,11 @@ fn run_playback(
                pw::spa::pod::Value::Choice(pw::spa::pod::ChoiceValue::Int(
                    pw::spa::utils::Choice(
                        pw::spa::utils::ChoiceFlags::empty(),
-                        pw::spa::utils::ChoiceEnum::Range { default: 8, min: 2, max: 64 },
+                        pw::spa::utils::ChoiceEnum::Range {
+                            default: 8,
+                            min: 2,
+                            max: 64,
+                        },
                    ),
                )),
            ),
@@ -524,15 +544,16 @@ fn run_playback(
        Pod::from_bytes(&buffers_values).unwrap(),
    ];

-    stream.connect(
-        spa::utils::Direction::Output,
-        None,
-        pw::stream::StreamFlags::AUTOCONNECT
-            | pw::stream::StreamFlags::MAP_BUFFERS
-            | pw::stream::StreamFlags::RT_PROCESS,
-        &mut params,
-    )
-    .map_err(|e| AudioError::Stream(e.to_string()))?;
+    stream
+        .connect(
+            spa::utils::Direction::Output,
+            None,
+            pw::stream::StreamFlags::AUTOCONNECT
+                | pw::stream::StreamFlags::MAP_BUFFERS
+                | pw::stream::StreamFlags::RT_PROCESS,
+            &mut params,
+        )
+        .map_err(|e| AudioError::Stream(e.to_string()))?;

    // Spawn a worker thread to read from rx and push to producer
    let running = Arc::new(AtomicBool::new(true));
@@ -607,7 +628,10 @@ fn run_playback(
 #[cfg(test)]
 mod tests {
    use super::{drain_loop, for_each_capture_sample, frames_to_produce, publish_frame};
-    use ringbuf::{HeapRb, traits::{Consumer, Producer, Split}};
+    use ringbuf::{
+        HeapRb,
+        traits::{Consumer, Producer, Split},
+    };
    use std::sync::atomic::{AtomicBool, AtomicU64, AtomicUsize, Ordering};
    use std::sync::{Arc, Mutex};
    use std::time::Duration;
@@ -647,9 +671,7 @@ mod tests {
    #[test]
    fn capture_size_larger_than_mapping_is_clamped() {
        let mut samples = Vec::new();
-        for_each_capture_sample(&[1, 0, 2, 0, 3], usize::MAX, |sample| {
-            samples.push(sample)
-        });
+        for_each_capture_sample(&[1, 0, 2, 0, 3], usize::MAX, |sample| samples.push(sample));
        assert_eq!(samples, vec![1, 2]);
    }

@@ -16,11 +16,20 @@ pub fn enumerate_audio_devices() -> Vec<AudioDevice> {
 /// Emits the in-progress node as an `AudioDevice` if it's a complete Audio/*
 /// node, then resets the accumulators for the next block. Non-audio or
 /// incomplete blocks are dropped (but still reset).
-fn push_device(name: &mut String, desc: &mut String, class: &mut String, out: &mut Vec<AudioDevice>) {
+fn push_device(
+    name: &mut String,
+    desc: &mut String,
+    class: &mut String,
+    out: &mut Vec<AudioDevice>,
+) {
    if !name.is_empty() && class.starts_with("Audio/") {
        out.push(AudioDevice {
            name: name.clone(),
-            description: if desc.is_empty() { name.clone() } else { desc.clone() },
+            description: if desc.is_empty() {
+                name.clone()
+            } else {
+                desc.clone()
+            },
            is_input: class == "Audio/Source",
        });
    }
@@ -44,7 +53,12 @@ fn parse_pw_nodes(text: &str) -> Vec<AudioDevice> {
    for line in text.lines() {
        let line = line.trim();
        if line.starts_with("id ") {
-            push_device(&mut current_name, &mut current_desc, &mut current_class, &mut devices);
+            push_device(
+                &mut current_name,
+                &mut current_desc,
+                &mut current_class,
+                &mut devices,
+            );
        } else if let Some(val) = line.strip_prefix("node.name = \"") {
            current_name = val.trim_end_matches('"').to_string();
        } else if let Some(val) = line.strip_prefix("node.description = \"") {
@@ -53,7 +67,12 @@ fn parse_pw_nodes(text: &str) -> Vec<AudioDevice> {
            current_class = val.trim_end_matches('"').to_string();
        }
    }
-    push_device(&mut current_name, &mut current_desc, &mut current_class, &mut devices);
+    push_device(
+        &mut current_name,
+        &mut current_desc,
+        &mut current_class,
+        &mut devices,
+    );

    devices.sort_by(|a, b| a.description.cmp(&b.description));
    devices
@@ -108,8 +127,14 @@ mod tests {
    fn source_is_input_sink_is_output() {
        let devices = parse_pw_nodes(SAMPLE_NODES);
        // Find devices by name or description to verify is_input
-        let mic = devices.iter().find(|d| d.name == "alsa_input.builtin").unwrap();
-        let speakers = devices.iter().find(|d| d.name == "alsa_output.builtin").unwrap();
+        let mic = devices
+            .iter()
+            .find(|d| d.name == "alsa_input.builtin")
+            .unwrap();
+        let speakers = devices
+            .iter()
+            .find(|d| d.name == "alsa_output.builtin")
+            .unwrap();
        let bare = devices.iter().find(|d| d.name == "bare.sink").unwrap();

        assert!(mic.is_input);
@@ -2,21 +2,26 @@
 //!
 //! Records the **full call as you experienced it**: the mixed incoming audio
 //! (everyone you hear) summed with your own transmitted mic, into a single mono
-//! WAV. Writing is driven by the playout mixer (one [`Recorder::write_frame`]
-//! per produced 20ms frame, paced by the hardware clock); your mic arrives
-//! separately from the capture thread via [`Recorder::push_mic`] and is buffered
-//! in a small FIFO so the two independently-clocked streams stay roughly aligned.
+//! WAV. Mixing/enqueue is driven by the playout mixer (one
+//! [`Recorder::write_frame`] per produced 20ms frame, paced by the hardware
+//! clock), while disk writes happen on a dedicated writer thread; your mic
+//! arrives separately from the capture thread via [`Recorder::push_mic`] and is
+//! buffered in a small FIFO so the two independently-clocked streams stay
+//! roughly aligned.
 //! Minor clock drift just slowly grows/shrinks that FIFO (capped, so the lag
 //! between your voice and the recording is bounded) — harmless for a voice
 //! recording, no realtime crackle concern.
 //!
 //! No external crates: the WAV writer emits the 44-byte canonical header itself
-//! and patches the two size fields on [`Recorder::finalize`].
+//! and patches the two size fields on the writer thread during
+//! [`Recorder::finalize`].

 use std::collections::VecDeque;
 use std::fs::{File, OpenOptions};
 use std::io::{self, Seek, SeekFrom, Write};
 use std::path::{Path, PathBuf};
+use std::sync::mpsc::{self, SyncSender, TrySendError};
+use std::thread::{self, JoinHandle};

 /// Capture sample rate (mono, 48kHz, matching the rest of the audio path).
 const SAMPLE_RATE: u32 = 48_000;
@@ -25,6 +30,8 @@ const CHANNELS: u16 = 1;
 const RIFF_DATA_OVERHEAD: u64 = 36;
 const MAX_RIFF_DATA_BYTES: u64 = u32::MAX as u64 - RIFF_DATA_OVERHEAD;
 const MAX_NAME_ATTEMPTS: usize = 1_000;
+const WRITER_QUEUE_FRAMES: usize = 256;
+const DROP_LOG_INTERVAL_FRAMES: u64 = 256;

 /// Cap on buffered mic samples (~200ms). Bounds how far recording lag can drift
 /// if the capture clock runs persistently faster than playout — past this we drop
@@ -118,13 +125,15 @@ impl WavWriter {
    }
 }

-/// A live call recorder: a [`WavWriter`] plus a small mic FIFO that aligns your
-/// transmitted mic with the playout mixer's incoming-mix frames.
+/// A live call recorder: a writer-thread queue plus a small mic FIFO that aligns
+/// your transmitted mic with the playout mixer's incoming-mix frames.
 pub struct Recorder {
-    writer: WavWriter,
+    frame_tx: SyncSender<Vec<i16>>,
+    writer_thread: JoinHandle<io::Result<()>>,
    /// Your transmitted mic samples, awaiting alignment with the next mix frame.
    mic_fifo: VecDeque<i16>,
    path: PathBuf,
+    dropped_frames: u64,
 }

 impl Recorder {
@@ -142,10 +151,15 @@ impl Recorder {
            let path = dir.join(name);
            match OpenOptions::new().write(true).create_new(true).open(&path) {
                Ok(file) => {
+                    let writer = WavWriter::from_file(file)?;
+                    let (frame_tx, frame_rx) = mpsc::sync_channel(WRITER_QUEUE_FRAMES);
+                    let writer_thread = thread::spawn(move || writer_thread_main(writer, frame_rx));
                    return Ok(Self {
-                        writer: WavWriter::from_file(file)?,
+                        frame_tx,
+                        writer_thread,
                        mic_fifo: VecDeque::new(),
                        path,
+                        dropped_frames: 0,
                    });
                }
                Err(e) if e.kind() == io::ErrorKind::AlreadyExists => continue,
@@ -179,21 +193,73 @@ impl Recorder {
    /// treated as silence (you weren't transmitting), so quiet stretches record
    /// the incoming mix alone.
    pub fn write_frame(&mut self, mixed: &[i16]) -> io::Result<()> {
-        let mut out = Vec::with_capacity(mixed.len());
-        for &m in mixed {
-            let mic = self.mic_fifo.pop_front().unwrap_or(0);
-            let sum = (m as i32 + mic as i32).clamp(i16::MIN as i32, i16::MAX as i32);
-            out.push(sum as i16);
+        let out = mix_with_mic(mixed, &mut self.mic_fifo);
+        match self.frame_tx.try_send(out) {
+            Ok(()) => Ok(()),
+            Err(TrySendError::Full(_)) => {
+                self.dropped_frames = self.dropped_frames.saturating_add(1);
+                if self.dropped_frames == 1
+                    || self.dropped_frames.is_multiple_of(DROP_LOG_INTERVAL_FRAMES)
+                {
+                    crate::log_msg(&format!(
+                        "recording: writer queue full; dropped {} frame(s)",
+                        self.dropped_frames
+                    ));
+                }
+                Ok(())
+            }
+            Err(TrySendError::Disconnected(_)) => Err(io::Error::new(
+                io::ErrorKind::BrokenPipe,
+                "recording writer thread stopped",
+            )),
        }
-        self.writer.write_samples(&out)
    }

    /// Finish the file, patching its size fields. Consumes the recorder.
    pub fn finalize(self) -> io::Result<()> {
-        self.writer.finalize()
+        let Self {
+            frame_tx,
+            writer_thread,
+            mic_fifo: _,
+            path: _,
+            dropped_frames: _,
+        } = self;
+        drop(frame_tx);
+        writer_thread
+            .join()
+            .unwrap_or_else(|_| Err(io::Error::other("recording writer thread panicked")))
    }
 }

+fn writer_thread_main(mut writer: WavWriter, frame_rx: mpsc::Receiver<Vec<i16>>) -> io::Result<()> {
+    let mut first_write_error = None;
+
+    for frame in frame_rx {
+        if first_write_error.is_none()
+            && let Err(e) = writer.write_samples(&frame)
+        {
+            first_write_error = Some(e);
+        }
+    }
+
+    let finalize_result = writer.finalize();
+    if let Some(e) = first_write_error {
+        Err(e)
+    } else {
+        finalize_result
+    }
+}
+
+fn mix_with_mic(mixed: &[i16], mic_fifo: &mut VecDeque<i16>) -> Vec<i16> {
+    let mut out = Vec::with_capacity(mixed.len());
+    for &m in mixed {
+        let mic = mic_fifo.pop_front().unwrap_or(0);
+        let sum = (m as i32 + mic as i32).clamp(i16::MIN as i32, i16::MAX as i32);
+        out.push(sum as i16);
+    }
+    out
+}
+
 /// Civil date (year, month, day) from a count of days since the Unix epoch.
 /// Howard Hinnant's `civil_from_days`; valid across the whole practical range.
 fn civil_from_days(z: i64) -> (i64, u32, u32) {
@@ -222,6 +288,23 @@ pub fn timestamp_filename(unix_secs: u64) -> String {
 #[cfg(test)]
 mod tests {
    use super::*;
+    use std::sync::atomic::{AtomicU64, Ordering};
+
+    static NEXT_TEMP_ID: AtomicU64 = AtomicU64::new(0);
+
+    fn unique_temp_dir(prefix: &str) -> PathBuf {
+        let id = NEXT_TEMP_ID.fetch_add(1, Ordering::Relaxed);
+        std::env::temp_dir().join(format!("{prefix}-{}-{id}", std::process::id()))
+    }
+
+    fn read_wav_samples(path: &Path) -> (Vec<u8>, Vec<i16>) {
+        let bytes = std::fs::read(path).unwrap();
+        let samples = bytes[44..]
+            .chunks_exact(2)
+            .map(|sample| i16::from_le_bytes([sample[0], sample[1]]))
+            .collect();
+        (bytes, samples)
+    }

    #[test]
    fn timestamp_filename_is_utc_and_padded() {
@@ -236,10 +319,7 @@ mod tests {

    #[test]
    fn same_second_recordings_get_unique_files_without_truncation() {
-        let dir = std::env::temp_dir().join(format!(
-            "peerspeak-collision-{}",
-            std::process::id()
-        ));
+        let dir = unique_temp_dir("peerspeak-collision");
        let _ = std::fs::remove_dir_all(&dir);
        std::fs::create_dir_all(&dir).unwrap();

@@ -258,6 +338,40 @@ mod tests {
        let _ = std::fs::remove_dir_all(&dir);
    }

+    #[test]
+    fn recorder_thread_writes_mixed_samples_and_header_on_finalize() {
+        let dir = unique_temp_dir("peerspeak-recorder-thread");
+        let _ = std::fs::remove_dir_all(&dir);
+        std::fs::create_dir_all(&dir).unwrap();
+
+        let mut recorder = Recorder::create(&dir, 1_700_000_123).unwrap();
+        let path = recorder.path().to_path_buf();
+
+        recorder.push_mic(&[1000, i16::MAX, -1000, i16::MIN, 2222]);
+        recorder.write_frame(&[10, 20, -32700]).unwrap();
+        recorder.push_mic(&[300, -300]);
+        recorder
+            .write_frame(&[0, 1000, i16::MAX, i16::MIN])
+            .unwrap();
+        recorder.finalize().unwrap();
+
+        let expected = vec![1010, i16::MAX, i16::MIN, i16::MIN, 3222, i16::MAX, i16::MIN];
+        let expected_data_bytes = u32::try_from(expected.len() * 2).unwrap();
+        let (bytes, samples) = read_wav_samples(&path);
+
+        assert_eq!(&bytes[0..4], b"RIFF");
+        assert_eq!(&bytes[8..12], b"WAVE");
+        assert_eq!(&bytes[36..40], b"data");
+        let riff = u32::from_le_bytes([bytes[4], bytes[5], bytes[6], bytes[7]]);
+        let data = u32::from_le_bytes([bytes[40], bytes[41], bytes[42], bytes[43]]);
+        assert_eq!(data, expected_data_bytes);
+        assert_eq!(riff, RIFF_DATA_OVERHEAD as u32 + expected_data_bytes);
+        assert_eq!(bytes.len(), 44 + expected.len() * 2);
+        assert_eq!(samples, expected);
+
+        let _ = std::fs::remove_dir_all(&dir);
+    }
+
    #[test]
    fn wav_header_round_trips_sizes() {
        let dir = std::env::temp_dir();
@@ -300,38 +414,32 @@ mod tests {

    #[test]
    fn mic_is_summed_with_mix_when_present() {
-        let dir = std::env::temp_dir();
-        let mut r = Recorder {
-            writer: WavWriter::new(&dir.join(format!("ps-sum-{}.wav", std::process::id())))
-                .unwrap(),
-            mic_fifo: VecDeque::new(),
-            path: PathBuf::new(),
-        };
-        r.push_mic(&[1000, 2000, 3000]);
-        // write_frame pops mic per-sample and sums; we can't read the file mid-stream,
-        // so assert the FIFO drains exactly by frame length.
-        r.write_frame(&[10, 20]).unwrap();
-        assert_eq!(r.mic_fifo.len(), 1, "two samples consumed, one mic left");
-        r.write_frame(&[0, 0]).unwrap();
+        let mut mic_fifo = VecDeque::from([1000, 2000, 3000]);
+
+        let first = mix_with_mic(&[10, 20], &mut mic_fifo);
+        assert_eq!(first, vec![1010, 2020]);
+        assert_eq!(mic_fifo.len(), 1, "two samples consumed, one mic left");
+
+        let second = mix_with_mic(&[0, 0], &mut mic_fifo);
+        assert_eq!(second, vec![3000, 0]);
        assert_eq!(
-            r.mic_fifo.len(),
+            mic_fifo.len(),
            0,
            "remaining mic sample consumed; rest is silence"
        );
-        let _ = r.finalize();
    }

    #[test]
    fn mic_fifo_is_capped() {
-        let dir = std::env::temp_dir();
-        let mut r = Recorder {
-            writer: WavWriter::new(&dir.join(format!("ps-cap-{}.wav", std::process::id())))
-                .unwrap(),
-            mic_fifo: VecDeque::new(),
-            path: PathBuf::new(),
-        };
+        let dir = unique_temp_dir("peerspeak-cap");
+        let _ = std::fs::remove_dir_all(&dir);
+        std::fs::create_dir_all(&dir).unwrap();
+
+        let mut r = Recorder::create(&dir, 1_700_000_001).unwrap();
        r.push_mic(&vec![5i16; MAX_MIC_FIFO * 2]);
        assert_eq!(r.mic_fifo.len(), MAX_MIC_FIFO, "FIFO is bounded to the cap");
-        let _ = r.finalize();
+        r.finalize().unwrap();
+
+        let _ = std::fs::remove_dir_all(&dir);
    }
 }
@@ -145,7 +145,10 @@ impl StereoPullResampler {
            self.frac -= 1.0;
        }
        let f = self.frac as f32;
-        let out = (lerp(self.prev.0, self.cur.0, f), lerp(self.prev.1, self.cur.1, f));
+        let out = (
+            lerp(self.prev.0, self.cur.0, f),
+            lerp(self.prev.1, self.cur.1, f),
+        );
        self.frac += self.step;
        Some(out)
    }
@@ -273,7 +276,10 @@ mod tests {
            }
        }
        // At step 2.0 we consume ~2 input frames per output frame.
-        assert!(idx > emitted, "consumed {idx} input, emitted {emitted} output");
+        assert!(
+            idx > emitted,
+            "consumed {idx} input, emitted {emitted} output"
+        );
    }

    /// A zero rate must not produce a zero `step` (which would spin `push`'s inner
@@ -185,10 +185,132 @@ pub fn initials(name: &str) -> String {
    }
 }

+/// A small content-addressed LRU cache mapping image bytes to a built value
+/// (e.g. an `iced` image handle), so the SAME value is reused across redraws
+/// instead of rebuilt every frame. Two Tier C F-03 properties beyond a plain
+/// hash map:
+///
+/// 1. **Bounded** — at most `cap` entries, evicting the least-recently-used on
+///    overflow, so a peer can't grow the cache without limit by publishing an
+///    endless stream of distinct valid avatars.
+/// 2. **Collision-safe** — a hit requires full byte equality, not just a matching
+///    64-bit hash, so a hash collision can never return a different image's value.
+///
+/// Linear scan; intended for small `cap` (tens of entries).
+pub struct ByteLru<V> {
+    cap: usize,
+    /// `(content hash, content bytes, value)`; back = most recently used.
+    entries: Vec<(u64, Vec<u8>, V)>,
+}
+
+impl<V: Clone> ByteLru<V> {
+    /// Create an LRU holding at most `cap` entries (`cap` is clamped to >= 1).
+    pub fn new(cap: usize) -> Self {
+        Self {
+            cap: cap.max(1),
+            entries: Vec::new(),
+        }
+    }
+
+    /// Return the cached value for these exact `bytes`, building and inserting it
+    /// on a miss (evicting the least-recently-used entry once over `cap`). A hit
+    /// verifies full byte equality, so a 64-bit hash collision never returns the
+    /// wrong value. A hit also refreshes the entry's recency.
+    pub fn get_or_insert(&mut self, bytes: &[u8], build: impl FnOnce() -> V) -> V {
+        use std::hash::{Hash, Hasher};
+        let mut hasher = std::collections::hash_map::DefaultHasher::new();
+        bytes.hash(&mut hasher);
+        self.get_or_insert_hashed(hasher.finish(), bytes, build)
+    }
+
+    /// Inner seam with the content `hash` supplied explicitly. Production callers
+    /// use [`get_or_insert`]; tests use this to force a hash collision (different
+    /// bytes, same hash) and exercise the byte-equality guard.
+    fn get_or_insert_hashed(&mut self, hash: u64, bytes: &[u8], build: impl FnOnce() -> V) -> V {
+        if let Some(idx) = self
+            .entries
+            .iter()
+            .position(|(h, b, _)| *h == hash && b.as_slice() == bytes)
+        {
+            // LRU touch: move the hit entry to the back (most recent).
+            let entry = self.entries.remove(idx);
+            let val = entry.2.clone();
+            self.entries.push(entry);
+            return val;
+        }
+
+        let val = build();
+        if self.entries.len() >= self.cap {
+            self.entries.remove(0); // evict least-recently-used
+        }
+        self.entries.push((hash, bytes.to_vec(), val.clone()));
+        val
+    }
+
+    #[cfg(test)]
+    fn len(&self) -> usize {
+        self.entries.len()
+    }
+}
+
 #[cfg(test)]
 mod tests {
    use super::*;

+    #[test]
+    fn byte_lru_reuses_value_for_identical_bytes() {
+        let mut lru: ByteLru<u32> = ByteLru::new(4);
+        let mut next = 0u32;
+        let mut build = |lru: &mut ByteLru<u32>, b: &[u8]| {
+            lru.get_or_insert(b, || {
+                next += 1;
+                next
+            })
+        };
+        // Same bytes → same value, built only once.
+        assert_eq!(build(&mut lru, b"alice"), 1);
+        assert_eq!(build(&mut lru, b"alice"), 1);
+        // Different bytes → a freshly built value.
+        assert_eq!(build(&mut lru, b"bob"), 2);
+        assert_eq!(lru.len(), 2);
+    }
+
+    #[test]
+    fn byte_lru_evicts_least_recently_used() {
+        let mut lru: ByteLru<u32> = ByteLru::new(2);
+        let mut n = 0u32;
+        let mut ins = |lru: &mut ByteLru<u32>, b: &[u8]| {
+            lru.get_or_insert(b, || {
+                n += 1;
+                n
+            })
+        };
+        ins(&mut lru, b"a"); // -> 1
+        ins(&mut lru, b"b"); // -> 2, cache = [a, b]
+        ins(&mut lru, b"a"); // touch a, cache = [b, a]
+        ins(&mut lru, b"c"); // evicts LRU (b), cache = [a, c]
+        assert_eq!(lru.len(), 2);
+        // `a` survived (recently touched) → still value 1, not rebuilt.
+        assert_eq!(ins(&mut lru, b"a"), 1);
+        // `b` was evicted → rebuilt with a new value.
+        assert_eq!(ins(&mut lru, b"b"), 4);
+    }
+
+    #[test]
+    fn byte_lru_byte_equality_survives_a_hash_collision() {
+        // Force the SAME 64-bit hash for two DIFFERENT byte strings (the case a
+        // bare-hash cache would alias — Tier C F-03 collision bug).
+        let mut lru: ByteLru<u32> = ByteLru::new(4);
+        assert_eq!(lru.get_or_insert_hashed(42, b"alice", || 1), 1);
+        // `bob` collides on the hash but differs in bytes → a MISS, built fresh,
+        // NOT aliased to alice's value.
+        assert_eq!(lru.get_or_insert_hashed(42, b"bob", || 2), 2);
+        // Both coexist; each re-lookup returns its own value (build closure unused).
+        assert_eq!(lru.get_or_insert_hashed(42, b"alice", || 99), 1);
+        assert_eq!(lru.get_or_insert_hashed(42, b"bob", || 99), 2);
+        assert_eq!(lru.len(), 2);
+    }
+
    #[test]
    fn initials_takes_first_two_words() {
        assert_eq!(initials("Alice"), "A");
@@ -230,7 +352,10 @@ mod tests {
    fn preset_png_in_range_and_out_of_range() {
        // Every declared preset index resolves to embedded bytes.
        for i in 0..PRESET_COUNT {
-            assert!(Avatar::Preset(i).preset_png().is_some(), "preset {i} missing");
+            assert!(
+                Avatar::Preset(i).preset_png().is_some(),
+                "preset {i} missing"
+            );
        }
        // Out-of-range index gracefully yields None (→ monogram fallback).
        assert!(Avatar::Preset(PRESET_COUNT).preset_png().is_none());
@@ -287,7 +412,10 @@ mod tests {
    #[test]
    fn sanitize_incoming_rejects_junk_and_oversize() {
        // Not valid base64 / not a PNG → downgraded to monogram.
-        assert_eq!(Avatar::Custom("not base64!!!".into()).sanitize_incoming(), Avatar::Monogram);
+        assert_eq!(
+            Avatar::Custom("not base64!!!".into()).sanitize_incoming(),
+            Avatar::Monogram
+        );
        // Over the byte cap → downgraded without even decoding.
        let huge = Avatar::Custom("A".repeat(CUSTOM_MAX_B64 + 1));
        assert_eq!(huge.sanitize_incoming(), Avatar::Monogram);
@@ -66,7 +66,10 @@ pub fn game_background_filename(game_id: &str) -> String {
 /// recedes the image so body text and panel chrome stay readable, and it re-tints
 /// per theme since `base` comes from the active palette.
 pub fn scrim_color(base: Color, dim: f32) -> Color {
-    Color { a: dim.clamp(0.0, 1.0), ..base }
+    Color {
+        a: dim.clamp(0.0, 1.0),
+        ..base
+    }
 }

 #[cfg(test)]
@@ -105,7 +105,11 @@ fn cmd_gen(args: &[String]) -> Result<(), String> {
        "pink" => generators::pink_noise(amp, len, seed),
        "impulse" => generators::impulse(amp, len),
        "silence" => generators::silence(len),
-        other => return Err(format!("unknown kind {other:?} (sine sweep white pink impulse silence)")),
+        other => {
+            return Err(format!(
+                "unknown kind {other:?} (sine sweep white pink impulse silence)"
+            ));
+        }
    };

    wav::write(Path::new(out), &samples, SAMPLE_RATE)?;
@@ -125,8 +129,12 @@ fn cmd_gen(args: &[String]) -> Result<(), String> {
 /// in which frequency range any residual lives.
 fn cmd_erle(args: &[String]) -> Result<(), String> {
    let (positional, flags) = parse_args(args);
-    let before = positional.first().ok_or("erle needs <before.wav> <after.wav>")?;
-    let after = positional.get(1).ok_or("erle needs <before.wav> <after.wav>")?;
+    let before = positional
+        .first()
+        .ok_or("erle needs <before.wav> <after.wav>")?;
+    let after = positional
+        .get(1)
+        .ok_or("erle needs <before.wav> <after.wav>")?;

    let b = wav::read(Path::new(before))?;
    let a = wav::read(Path::new(after))?;
@@ -239,17 +247,34 @@ fn cmd_aec(args: &[String]) -> Result<(), String> {
        1000.0 * tail as f32 / sr as f32,
        metrics::dbfs(atten),
    );
-    println!("  filter: {taps} taps, mu {mu}{}", if has_near { " (with near-end / double-talk)" } else { "" });
+    println!(
+        "  filter: {taps} taps, mu {mu}{}",
+        if has_near {
+            " (with near-end / double-talk)"
+        } else {
+            ""
+        }
+    );
    if has_near {
        let dtd = if flags.present("no-dtd") { "off" } else { "on" };
        println!(
            "  double-talk: detector {dtd}, threshold {dtd_threshold}, flagged {:.0}% of samples{}",
            100.0 * canceller.double_talk_rate(),
-            if onset > 0 { format!(", near-end onset {:.1}s", onset as f32 / sr as f32) } else { String::new() },
+            if onset > 0 {
+                format!(", near-end onset {:.1}s", onset as f32 / sr as f32)
+            } else {
+                String::new()
+            },
        );
    }
-    println!("  mic before: {:.1} dBFS rms", metrics::dbfs(metrics::rms(&mic)));
-    println!("  residual echo after: {:.1} dBFS rms", metrics::dbfs(metrics::rms(&residual)));
+    println!(
+        "  mic before: {:.1} dBFS rms",
+        metrics::dbfs(metrics::rms(&mic))
+    );
+    println!(
+        "  residual echo after: {:.1} dBFS rms",
+        metrics::dbfs(metrics::rms(&residual))
+    );
    println!("  ERLE broadband: {broadband:+.1} dB");
    println!("  ERLE early/late: {early:+.1} -> {late:+.1} dB  (rise = filter converging)");

@@ -278,9 +303,21 @@ fn cmd_aec(args: &[String]) -> Result<(), String> {
    }
    if flags.present("show") {
        println!("\n--- mic (echo present) ---");
-        print!("{}", render::render(&stft::analyze(&mic, sr, 2048, 512), &render::RenderOpts::default()));
+        print!(
+            "{}",
+            render::render(
+                &stft::analyze(&mic, sr, 2048, 512),
+                &render::RenderOpts::default()
+            )
+        );
        println!("\n--- cleaned (post-AEC) ---");
-        print!("{}", render::render(&stft::analyze(&cleaned, sr, 2048, 512), &render::RenderOpts::default()));
+        print!(
+            "{}",
+            render::render(
+                &stft::analyze(&cleaned, sr, 2048, 512),
+                &render::RenderOpts::default()
+            )
+        );
    }
    Ok(())
 }
@@ -339,13 +376,22 @@ impl Flags {
        self.bools.iter().any(|b| b == key) || self.map.contains_key(key)
    }
    fn f32_or(&self, key: &str, default: f32) -> f32 {
-        self.map.get(key).and_then(|v| v.parse().ok()).unwrap_or(default)
+        self.map
+            .get(key)
+            .and_then(|v| v.parse().ok())
+            .unwrap_or(default)
    }
    fn usize_or(&self, key: &str, default: usize) -> usize {
-        self.map.get(key).and_then(|v| v.parse().ok()).unwrap_or(default)
+        self.map
+            .get(key)
+            .and_then(|v| v.parse().ok())
+            .unwrap_or(default)
    }
    fn u64_or(&self, key: &str, default: u64) -> u64 {
-        self.map.get(key).and_then(|v| v.parse().ok()).unwrap_or(default)
+        self.map
+            .get(key)
+            .and_then(|v| v.parse().ok())
+            .unwrap_or(default)
    }
 }

@@ -1,9 +1,6 @@
-use peerspeak::network::{
-    gossip::IrohGossipState,
-    RoomState, PeerState,
-};
 use iroh::{Endpoint, endpoint::presets};
 use iroh_gossip::net::Gossip;
+use peerspeak::network::{PeerState, RoomState, gossip::IrohGossipState};
 use tokio::time::{self, Duration};

 #[tokio::main]
@@ -18,7 +15,7 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
        .address_lookup(lookup_a.clone())
        .bind()
        .await?;
-    
+
    endpoint_a.online().await;
    println!("Node A online. ID: {}", endpoint_a.id());

@@ -27,7 +24,12 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
        .accept(iroh_gossip::net::GOSSIP_ALPN, gossip_a.clone())
        .spawn();

-    let room_a = IrohGossipState::new(endpoint_a.clone(), gossip_a.clone(), lookup_a.clone(), secret_a);
+    let room_a = IrohGossipState::new(
+        endpoint_a.clone(),
+        gossip_a.clone(),
+        lookup_a.clone(),
+        secret_a,
+    );

    // 2. Node B (Client) Setup
    let lookup_b = iroh::address_lookup::memory::MemoryLookup::new();
@@ -46,7 +48,12 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
        .accept(iroh_gossip::net::GOSSIP_ALPN, gossip_b.clone())
        .spawn();

-    let room_b = IrohGossipState::new(endpoint_b.clone(), gossip_b.clone(), lookup_b.clone(), secret_b);
+    let room_b = IrohGossipState::new(
+        endpoint_b.clone(),
+        gossip_b.clone(),
+        lookup_b.clone(),
+        secret_b,
+    );

    // 3. Create room on Node A
    let topic_id = rand::random();
@@ -65,6 +72,7 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
        sharing: None,
        avatar: Default::default(),
        game: None,
+        music: None,
    };
    room_a.join(&ticket_str, state_a, vec![]).await?;
    println!("Node A joined topic.");
@@ -85,6 +93,7 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
        sharing: None,
        avatar: Default::default(),
        game: None,
+        music: None,
    };
    room_b.join(&ticket_str, state_b, vec![]).await?;
    println!("Node B joined topic.");
@@ -20,6 +20,9 @@ pub trait AudioDecoder: Send {
    /// If `compressed` is `None` (or `Some(&[])`), it indicates packet loss,
    /// enabling the decoder to perform packet loss concealment (PLC).
    fn decode(&mut self, compressed: Option<&[u8]>) -> Result<Vec<i16>, CodecError>;
+
+    /// Reconstructs the previous lost frame from the next packet's in-band FEC.
+    fn decode_fec(&mut self, next_payload: &[u8]) -> Result<Vec<i16>, CodecError>;
 }

 pub mod opus_impl;
@@ -1,5 +1,49 @@
-use crate::codec::{AudioEncoder, AudioDecoder, CodecError};
-use opus::{Encoder, Decoder, Application, Channels};
+use crate::codec::{AudioDecoder, AudioEncoder, CodecError};
+use crate::config::AudioProfile;
+use opus::{Application, Bitrate, Channels, Decoder, Encoder};
+
+/// Concrete libopus encoder settings derived from an [`AudioProfile`]. Plain
+/// data, so the profile→params mapping ([`opus_params`]) stays a pure,
+/// unit-testable function (W12).
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub struct OpusParams {
+    /// Target bitrate in bits/sec.
+    pub bitrate: i32,
+    /// Enable in-band forward error correction (loss redundancy in the bitstream).
+    pub inband_fec: bool,
+    /// Expected packet-loss percentage (0..=100); tunes how much FEC libopus adds.
+    pub packet_loss_perc: i32,
+    /// Discontinuous transmission: stop sending during silence to save bandwidth.
+    pub dtx: bool,
+}
+
+/// Map a named profile to concrete Opus parameters. Pure — the W12 testable seam.
+///
+/// `BadNetwork` deliberately runs a *lower* bitrate than `Balanced`: in-band FEC
+/// redundancy is carried inside the same bitstream, so trimming the base bitrate
+/// leaves headroom for the redundancy on a congested link.
+pub fn opus_params(profile: AudioProfile) -> OpusParams {
+    match profile {
+        AudioProfile::LowLatency => OpusParams {
+            bitrate: 24_000,
+            inband_fec: false,
+            packet_loss_perc: 0,
+            dtx: false,
+        },
+        AudioProfile::Balanced => OpusParams {
+            bitrate: 32_000,
+            inband_fec: true,
+            packet_loss_perc: 10,
+            dtx: false,
+        },
+        AudioProfile::BadNetwork => OpusParams {
+            bitrate: 20_000,
+            inband_fec: true,
+            packet_loss_perc: 25,
+            dtx: false,
+        },
+    }
+}

 pub struct OpusEncoder {
    encoder: Encoder,
@@ -8,11 +52,38 @@ pub struct OpusEncoder {
 impl OpusEncoder {
    /// Creates a new Opus encoder.
    /// Standard voice parameters: sample_rate = 48000, channels = Channels::Mono, application = Application::Voip
-    pub fn new(sample_rate: u32, channels: Channels, application: Application) -> Result<Self, CodecError> {
+    pub fn new(
+        sample_rate: u32,
+        channels: Channels,
+        application: Application,
+    ) -> Result<Self, CodecError> {
        let encoder = Encoder::new(sample_rate, channels, application)
            .map_err(|e| CodecError::Init(format!("Failed to create Opus encoder: {}", e)))?;
        Ok(Self { encoder })
    }
+
+    /// Apply concrete codec parameters to the live encoder. Safe to call between
+    /// frames, so the user can switch profile mid-call.
+    pub fn apply_params(&mut self, params: &OpusParams) -> Result<(), CodecError> {
+        self.encoder
+            .set_bitrate(Bitrate::Bits(params.bitrate))
+            .map_err(|e| CodecError::Init(format!("set_bitrate: {}", e)))?;
+        self.encoder
+            .set_inband_fec(params.inband_fec)
+            .map_err(|e| CodecError::Init(format!("set_inband_fec: {}", e)))?;
+        self.encoder
+            .set_packet_loss_perc(params.packet_loss_perc)
+            .map_err(|e| CodecError::Init(format!("set_packet_loss_perc: {}", e)))?;
+        self.encoder
+            .set_dtx(params.dtx)
+            .map_err(|e| CodecError::Init(format!("set_dtx: {}", e)))?;
+        Ok(())
+    }
+
+    /// Apply a named [`AudioProfile`] (shorthand for `apply_params(&opus_params(p))`).
+    pub fn apply_profile(&mut self, profile: AudioProfile) -> Result<(), CodecError> {
+        self.apply_params(&opus_params(profile))
+    }
 }

 impl AudioEncoder for OpusEncoder {
@@ -20,9 +91,11 @@ impl AudioEncoder for OpusEncoder {
        // We allocate a buffer for the compressed output.
        // A maximum packet size of 4000 bytes is more than enough for a single voice frame.
        let mut compressed = vec![0u8; 4000];
-        let len = self.encoder.encode(pcm, &mut compressed)
+        let len = self
+            .encoder
+            .encode(pcm, &mut compressed)
            .map_err(|e| CodecError::Encode(format!("Opus encoding failed: {}", e)))?;
-        
+
        compressed.truncate(len);
        Ok(compressed)
    }
@@ -42,10 +115,18 @@ impl OpusDecoder {
    /// Creates a new Opus decoder.
    /// Standard voice parameters: sample_rate = 48000, channels = Channels::Mono.
    /// `frame_samples` is the per-channel length of one transmitted frame (e.g. 960).
-    pub fn new(sample_rate: u32, channels: Channels, frame_samples: usize) -> Result<Self, CodecError> {
+    pub fn new(
+        sample_rate: u32,
+        channels: Channels,
+        frame_samples: usize,
+    ) -> Result<Self, CodecError> {
        let decoder = Decoder::new(sample_rate, channels)
            .map_err(|e| CodecError::Init(format!("Failed to create Opus decoder: {}", e)))?;
-        Ok(Self { decoder, channels, frame_samples })
+        Ok(Self {
+            decoder,
+            channels,
+            frame_samples,
+        })
    }

    fn channels_count(&self) -> usize {
@@ -73,18 +154,72 @@ impl AudioDecoder for OpusDecoder {
            }
        };

-        let decoded_per_channel = self.decoder.decode(input, &mut pcm, false)
+        let decoded_per_channel = self
+            .decoder
+            .decode(input, &mut pcm, false)
            .map_err(|e| CodecError::Decode(format!("Opus decoding failed: {}", e)))?;

        pcm.truncate(decoded_per_channel * channels_count);
        Ok(pcm)
    }
+
+    fn decode_fec(&mut self, next_payload: &[u8]) -> Result<Vec<i16>, CodecError> {
+        let channels_count = self.channels_count();
+        let mut pcm = vec![0i16; self.frame_samples * channels_count];
+
+        let decoded_per_channel = self
+            .decoder
+            .decode(next_payload, &mut pcm, true)
+            .map_err(|e| CodecError::Decode(format!("Opus FEC decoding failed: {}", e)))?;
+
+        pcm.truncate(decoded_per_channel * channels_count);
+        Ok(pcm)
+    }
 }

 #[cfg(test)]
 mod tests {
    use super::*;

+    #[test]
+    fn test_opus_params_mapping() {
+        let low = opus_params(AudioProfile::LowLatency);
+        let bal = opus_params(AudioProfile::Balanced);
+        let bad = opus_params(AudioProfile::BadNetwork);
+
+        // LowLatency has no loss redundancy; the other two do.
+        assert!(!low.inband_fec);
+        assert_eq!(low.packet_loss_perc, 0);
+        assert!(bal.inband_fec);
+        assert!(bad.inband_fec);
+
+        // Capture-side gating suppresses silence; no profile adds Opus DTX.
+        assert!(!low.dtx && !bal.dtx && !bad.dtx);
+        assert!(bad.packet_loss_perc > bal.packet_loss_perc);
+
+        // BadNetwork trims base bitrate to make room for FEC redundancy.
+        assert!(bad.bitrate < bal.bitrate);
+
+        // All bitrates are sane positive voice rates.
+        for p in [low, bal, bad] {
+            assert!(p.bitrate > 0 && p.bitrate <= 64_000);
+            assert!((0..=100).contains(&p.packet_loss_perc));
+        }
+    }
+
+    #[test]
+    fn test_apply_profile_sets_bitrate() {
+        let mut encoder = OpusEncoder::new(48000, Channels::Mono, Application::Voip).unwrap();
+        // Every profile applies cleanly to a real encoder...
+        for profile in AudioProfile::ALL {
+            encoder.apply_profile(profile).unwrap();
+        }
+        // ...and the last-applied bitrate is reflected by the encoder.
+        encoder.apply_profile(AudioProfile::Balanced).unwrap();
+        let want = opus_params(AudioProfile::Balanced).bitrate;
+        assert_eq!(encoder.encoder.get_bitrate().unwrap(), Bitrate::Bits(want));
+    }
+
    #[test]
    fn test_round_trip() {
        let mut encoder = OpusEncoder::new(48000, Channels::Mono, Application::Voip).unwrap();
@@ -100,7 +235,10 @@ mod tests {

        // encode it
        let compressed = encoder.encode(&pcm).unwrap();
-        assert!(!compressed.is_empty(), "Compressed buffer should not be empty");
+        assert!(
+            !compressed.is_empty(),
+            "Compressed buffer should not be empty"
+        );
        assert!(
            compressed.len() < pcm.len() * std::mem::size_of::<i16>(),
            "Compressed size ({}) should be smaller than raw PCM size ({})",
@@ -110,13 +248,21 @@ mod tests {

        // decode it
        let decoded = decoder.decode(Some(&compressed)).unwrap();
-        assert_eq!(decoded.len(), 960, "Decoded sample count should be exactly 960");
+        assert_eq!(
+            decoded.len(),
+            960,
+            "Decoded sample count should be exactly 960"
+        );

        // 2. Round-trip carries signal energy (not silence)
        let sum_sq: f64 = decoded.iter().map(|&x| (x as f64).powi(2)).sum();
        let rms = (sum_sq / decoded.len() as f64).sqrt();
        // Since input had amplitude ~10000, let's verify RMS is significantly above 0 (e.g. > 100.0)
-        assert!(rms > 100.0, "Decoded signal should carry energy (RMS was {})", rms);
+        assert!(
+            rms > 100.0,
+            "Decoded signal should carry energy (RMS was {})",
+            rms
+        );
    }

    #[test]
@@ -125,11 +271,19 @@ mod tests {

        // decode(None) returns exactly frame_samples (960) samples
        let plc_none = decoder.decode(None).unwrap();
-        assert_eq!(plc_none.len(), 960, "decode(None) should yield exactly 960 samples");
+        assert_eq!(
+            plc_none.len(),
+            960,
+            "decode(None) should yield exactly 960 samples"
+        );

        // decode(Some(&[])) (empty slice) does the same
        let plc_empty = decoder.decode(Some(&[])).unwrap();
-        assert_eq!(plc_empty.len(), 960, "decode(Some(&[])) should yield exactly 960 samples");
+        assert_eq!(
+            plc_empty.len(),
+            960,
+            "decode(Some(&[])) should yield exactly 960 samples"
+        );
    }

    #[test]
@@ -140,7 +294,11 @@ mod tests {
        let pcm = vec![0i16; 960];
        let compressed = encoder.encode(&pcm).unwrap();
        let decoded = decoder.decode(Some(&compressed)).unwrap();
-        assert_eq!(decoded.len(), 960, "Decoded sample count should match packet duration");
+        assert_eq!(
+            decoded.len(),
+            960,
+            "Decoded sample count should match packet duration"
+        );
    }

    #[test]
@@ -149,11 +307,18 @@ mod tests {

        // decode(None) returns exactly frame_samples * 2 (1920) samples
        let plc_none = decoder.decode(None).unwrap();
-        assert_eq!(plc_none.len(), 960 * 2, "Stereo decode(None) should yield exactly 1920 samples");
+        assert_eq!(
+            plc_none.len(),
+            960 * 2,
+            "Stereo decode(None) should yield exactly 1920 samples"
+        );

        // decode(Some(&[])) (empty slice) does the same
        let plc_empty = decoder.decode(Some(&[])).unwrap();
-        assert_eq!(plc_empty.len(), 960 * 2, "Stereo decode(Some(&[])) should yield exactly 1920 samples");
+        assert_eq!(
+            plc_empty.len(),
+            960 * 2,
+            "Stereo decode(Some(&[])) should yield exactly 1920 samples"
+        );
    }
 }
-
@@ -1,9 +1,12 @@
 use crate::notify::Sound;
 use crate::theme::AppTheme;
+use anyhow::Context;
 use serde::{Deserialize, Serialize};
 use std::collections::{BTreeMap, HashMap};
 use std::fs;
-use std::path::PathBuf;
+use std::io::Write;
+use std::path::{Path, PathBuf};
+use std::time::{SystemTime, UNIX_EPOCH};

 /// Relay/discovery posture, trading connectivity against how much the n0
 /// infrastructure learns about you. See the network module for details.
@@ -24,8 +27,11 @@ pub enum NetworkMode {

 impl NetworkMode {
    /// All variants, for presentation in a picker.
-    pub const ALL: [NetworkMode; 3] =
-        [NetworkMode::RelayNoDiscovery, NetworkMode::N0Full, NetworkMode::DirectOnly];
+    pub const ALL: [NetworkMode; 3] = [
+        NetworkMode::RelayNoDiscovery,
+        NetworkMode::N0Full,
+        NetworkMode::DirectOnly,
+    ];
 }

 /// Arrangement of the in-call room screen, chosen via the layout picker.
@@ -42,8 +48,11 @@ pub enum RoomLayout {

 impl RoomLayout {
    /// All variants, in picker display order.
-    pub const ALL: [RoomLayout; 3] =
-        [RoomLayout::ThreeColumn, RoomLayout::BottomDock, RoomLayout::Drawer];
+    pub const ALL: [RoomLayout; 3] = [
+        RoomLayout::ThreeColumn,
+        RoomLayout::BottomDock,
+        RoomLayout::Drawer,
+    ];
 }

 /// What a call recording captures. `Mixed` is the original single-file behaviour;
@@ -62,8 +71,11 @@ pub enum RecordingMode {

 impl RecordingMode {
    /// All variants, in picker display order.
-    pub const ALL: [RecordingMode; 3] =
-        [RecordingMode::Mixed, RecordingMode::Multitrack, RecordingMode::Both];
+    pub const ALL: [RecordingMode; 3] = [
+        RecordingMode::Mixed,
+        RecordingMode::Multitrack,
+        RecordingMode::Both,
+    ];

    /// True when this mode writes per-peer stem tracks (Multitrack or Both).
    pub fn is_multitrack(self) -> bool {
@@ -81,6 +93,60 @@ impl std::fmt::Display for RecordingMode {
    }
 }

+/// Named Opus encoder / network-resilience policy (W12). The user picks a
+/// profile instead of raw codec knobs; the concrete libopus parameters live in
+/// `codec::opus_impl::opus_params`. Applies live to the running encoder.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize, Default)]
+pub enum AudioProfile {
+    /// Lowest mouth-to-ear delay: modest bitrate, no FEC redundancy. Best on a
+    /// clean LAN / low-loss link where added latency matters more than loss.
+    LowLatency,
+    /// Sensible default: voice bitrate with in-band FEC for light packet loss.
+    #[default]
+    Balanced,
+    /// Maximum resilience on a lossy/congested link: in-band FEC tuned for heavy
+    /// loss, at a lower bitrate to leave headroom for the redundancy.
+    BadNetwork,
+}
+
+impl AudioProfile {
+    /// All variants, in picker display order.
+    pub const ALL: [AudioProfile; 3] = [
+        AudioProfile::LowLatency,
+        AudioProfile::Balanced,
+        AudioProfile::BadNetwork,
+    ];
+
+    /// Compact discriminant for handing the profile to the capture thread via an
+    /// atomic. Pairs with [`AudioProfile::from_u8`].
+    pub fn as_u8(self) -> u8 {
+        match self {
+            AudioProfile::LowLatency => 0,
+            AudioProfile::Balanced => 1,
+            AudioProfile::BadNetwork => 2,
+        }
+    }
+
+    /// Inverse of [`AudioProfile::as_u8`]; unknown values fall back to the default.
+    pub fn from_u8(v: u8) -> AudioProfile {
+        match v {
+            0 => AudioProfile::LowLatency,
+            2 => AudioProfile::BadNetwork,
+            _ => AudioProfile::Balanced,
+        }
+    }
+}
+
+impl std::fmt::Display for AudioProfile {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.write_str(match self {
+            AudioProfile::LowLatency => "Low latency",
+            AudioProfile::Balanced => "Balanced",
+            AudioProfile::BadNetwork => "Bad network",
+        })
+    }
+}
+
 impl std::fmt::Display for RoomLayout {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        f.write_str(match self {
@@ -102,6 +168,139 @@ impl std::fmt::Display for NetworkMode {
    }
 }

+/// Pixelpass host quality preset for screen shares. `Auto` leaves pixelpass free
+/// to choose from its bandwidth pre-flight; fixed presets are passed as CLI flags.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize, Default)]
+#[serde(rename_all = "snake_case")]
+pub enum ShareQuality {
+    #[default]
+    Auto,
+    Low,
+    Medium,
+    High,
+    Source,
+}
+
+impl ShareQuality {
+    pub const ALL: [ShareQuality; 5] = [
+        ShareQuality::Auto,
+        ShareQuality::Low,
+        ShareQuality::Medium,
+        ShareQuality::High,
+        ShareQuality::Source,
+    ];
+}
+
+impl std::fmt::Display for ShareQuality {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.write_str(match self {
+            ShareQuality::Auto => "Auto",
+            ShareQuality::Low => "Low",
+            ShareQuality::Medium => "Medium",
+            ShareQuality::High => "High",
+            ShareQuality::Source => "Source",
+        })
+    }
+}
+
+/// Preferred local player for watching a peer's screen share.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize, Default)]
+#[serde(rename_all = "snake_case")]
+pub enum SharePlayer {
+    #[default]
+    Mpv,
+    Vlc,
+}
+
+impl SharePlayer {
+    pub const ALL: [SharePlayer; 2] = [SharePlayer::Mpv, SharePlayer::Vlc];
+}
+
+impl std::fmt::Display for SharePlayer {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.write_str(match self {
+            SharePlayer::Mpv => "mpv",
+            SharePlayer::Vlc => "VLC",
+        })
+    }
+}
+
+/// Local player buffering posture for screen-share playback.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize, Default)]
+#[serde(rename_all = "snake_case")]
+pub enum ShareBuffering {
+    #[default]
+    LowLatency,
+    Smooth,
+}
+
+impl ShareBuffering {
+    pub const ALL: [ShareBuffering; 2] = [ShareBuffering::LowLatency, ShareBuffering::Smooth];
+}
+
+impl std::fmt::Display for ShareBuffering {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.write_str(match self {
+            ShareBuffering::LowLatency => "Low latency",
+            ShareBuffering::Smooth => "Smooth",
+        })
+    }
+}
+
+fn default_screen_share_cache_mb() -> u32 {
+    2
+}
+
+/// Local-only screen-share preferences. Host fields become pixelpass host CLI
+/// flags; viewer fields shape local mpv/VLC launch. None/empty/default values
+/// deliberately let pixelpass/player defaults stand.
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
+pub struct ScreenShareSettings {
+    #[serde(default)]
+    pub quality: ShareQuality,
+    #[serde(default)]
+    pub bitrate_mbps: Option<u32>,
+    #[serde(default)]
+    pub framerate: Option<u32>,
+    #[serde(default)]
+    pub max_height: Option<u32>,
+    #[serde(default)]
+    pub max_viewers: Option<u32>,
+    #[serde(default)]
+    pub force_software_encode: bool,
+    #[serde(default)]
+    pub extra_host_args: String,
+    #[serde(default)]
+    pub player: SharePlayer,
+    #[serde(default)]
+    pub hardware_decode: bool,
+    #[serde(default)]
+    pub buffering: ShareBuffering,
+    #[serde(default = "default_screen_share_cache_mb")]
+    pub cache_mb: u32,
+    #[serde(default)]
+    pub extra_mpv_args: String,
+}
+
+impl Default for ScreenShareSettings {
+    fn default() -> Self {
+        Self {
+            quality: ShareQuality::default(),
+            bitrate_mbps: None,
+            framerate: None,
+            max_height: None,
+            max_viewers: None,
+            force_software_encode: false,
+            extra_host_args: String::new(),
+            player: SharePlayer::default(),
+            hardware_decode: false,
+            buffering: ShareBuffering::default(),
+            cache_mb: default_screen_share_cache_mb(),
+            extra_mpv_args: String::new(),
+        }
+    }
+}
+
 fn default_true() -> bool {
    true
 }
@@ -126,6 +325,10 @@ fn default_chat_height() -> f32 {
    180.0
 }

+fn default_threecol_playlist_height() -> f32 {
+    220.0
+}
+
 fn default_controls_width() -> f32 {
    280.0
 }
@@ -134,6 +337,10 @@ fn default_chat_drawer_width() -> f32 {
    320.0
 }

+fn default_playlist_drawer_width() -> f32 {
+    320.0
+}
+
 fn default_window_width() -> f32 {
    900.0
 }
@@ -156,8 +363,33 @@ pub struct AppConfig {
    /// App-internal playback gain applied to the mixed output (1.0 = unity).
    #[serde(default = "default_volume")]
    pub output_volume: f32,
+    /// Universal playback gain for inline chat audio clips (1.0 = unity). One
+    /// level shared by every uploaded clip so the slider sticks across plays.
+    #[serde(default = "default_volume")]
+    pub clip_volume: f32,
+    /// W22 music: the user's personal playlist as local file PATHS (not bytes).
+    /// Loaded into memory at startup; missing files are skipped/marked on play.
+    #[serde(default)]
+    pub music_playlist: Vec<String>,
+    /// W22 music: local playback gain for the dedicated music player (1.0 = unity).
+    #[serde(default = "default_volume")]
+    pub music_volume: f32,
+    /// W22 music: opt-in shared listening broadcast toggle. Local preference.
+    #[serde(default)]
+    pub music_broadcast: bool,
+    /// Show the slim now-playing player bar in the room screen.
+    #[serde(default = "default_true")]
+    pub show_player_bar: bool,
+    /// When true, `clip_volume` governs every clip. When false, each clip keeps
+    /// its own (in-memory) level and the universal slider is inactive.
+    #[serde(default = "default_true")]
+    pub clip_volume_universal: bool,
    #[serde(default)]
    pub network_mode: NetworkMode,
+    /// Opus encoder / network-resilience profile (W12). Applies live to the
+    /// running encoder; default `Balanced`.
+    #[serde(default)]
+    pub audio_profile: AudioProfile,
    /// Presence posture for the friends idle listener (W7): invisible / normal /
    /// discoverable. Default `Normal` = answer friends only, no DNS beacon.
    #[serde(default)]
@@ -174,12 +406,20 @@ pub struct AppConfig {
    pub participants_width: f32,
    #[serde(default = "default_chat_height")]
    pub chat_height: f32,
+    /// Height (px) of the standalone Playlist card stacked under Chat in the
+    /// 3-column layout. Resized via its own horizontal divider; re-clamped to the
+    /// window on load/resize. Only used by `RoomLayout::ThreeColumn`.
+    #[serde(default = "default_threecol_playlist_height")]
+    pub threecol_playlist_height: f32,
    /// Controls panel width for the 3-column layout (px).
    #[serde(default = "default_controls_width")]
    pub controls_width: f32,
    /// Chat drawer width for the drawer layout (px).
    #[serde(default = "default_chat_drawer_width")]
    pub chat_drawer_width: f32,
+    /// Playlist drawer width for the room-screen right-edge music panel (px).
+    #[serde(default = "default_playlist_drawer_width")]
+    pub playlist_drawer_width: f32,
    /// Chosen arrangement of the in-call room screen.
    #[serde(default)]
    pub room_layout: RoomLayout,
@@ -262,6 +502,9 @@ pub struct AppConfig {
    /// Empty / unset = look it up on `$PATH`. Hand-editable; no Settings UI yet.
    #[serde(default)]
    pub pixelpass_path: Option<String>,
+    /// Local-only host/player controls for screen sharing.
+    #[serde(default)]
+    pub screen_share: ScreenShareSettings,
    /// Recently-joined rooms (W7), most-recent-first. Purely local UI state for a
    /// one-click rejoin; never sent over the wire. De-duped by room topic and
    /// capped (see `recents`). Defaulted empty so older configs upgrade cleanly.
@@ -279,6 +522,11 @@ pub struct AppConfig {
    /// string. Local preference only; never sent to peers. Absent entry = unity.
    #[serde(default)]
    pub peer_volume: HashMap<String, f32>,
+    /// Per-source music listen volume/gain (`1.0` = unity), keyed by peer node id
+    /// string. Local preference only; never sent to peers. Absent entry falls
+    /// back to `music_volume`.
+    #[serde(default)]
+    pub music_source_volume: HashMap<String, f32>,
    /// Per-peer listener-side noise-gate threshold (normalized RMS, `0.0` = off),
    /// keyed by peer node id string. Local preference only; never sent to peers.
    /// Absent entry = gate disabled (pass-through).
@@ -303,6 +551,13 @@ pub struct AppConfig {
    pub window_y: Option<i32>,
 }

+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum LoadOutcome {
+    Missing,
+    Loaded,
+    Recovered,
+}
+
 impl Default for AppConfig {
    fn default() -> Self {
        Self {
@@ -312,14 +567,23 @@ impl Default for AppConfig {
            noise_gate_threshold: 0.01,
            input_volume: 1.0,
            output_volume: 1.0,
+            clip_volume: 1.0,
+            music_playlist: Vec::new(),
+            music_volume: 1.0,
+            music_broadcast: false,
+            show_player_bar: true,
+            clip_volume_universal: true,
            network_mode: NetworkMode::default(),
+            audio_profile: AudioProfile::default(),
            presence_mode: crate::presence::PresenceMode::default(),
            echo_cancellation_enabled: false,
            notifications_enabled: true,
            participants_width: default_participants_width(),
            chat_height: default_chat_height(),
+            threecol_playlist_height: default_threecol_playlist_height(),
            controls_width: default_controls_width(),
            chat_drawer_width: default_chat_drawer_width(),
+            playlist_drawer_width: default_playlist_drawer_width(),
            room_layout: RoomLayout::default(),
            theme: AppTheme::default(),
            avatar: crate::avatar::Avatar::default(),
@@ -346,10 +610,12 @@ impl Default for AppConfig {
            sound_mic_toggle_enabled: true,
            sound_reconnect_failed_enabled: true,
            pixelpass_path: None,
+            screen_share: ScreenShareSettings::default(),
            recents: Vec::new(),
            peer_eq: HashMap::new(),
            peer_pan: HashMap::new(),
            peer_volume: HashMap::new(),
+            music_source_volume: HashMap::new(),
            peer_gate: HashMap::new(),
            hotkeys: crate::hotkeys::HotkeyMap::default(),
            window_width: default_window_width(),
@@ -424,24 +690,115 @@ impl AppConfig {
    }

    pub fn load() -> Self {
-        if let Some(path) = Self::config_path()
-            && let Ok(contents) = fs::read_to_string(&path)
-                && let Ok(config) = serde_json::from_str(&contents) {
-                    return config;
-                }
-        Self::default()
+        let Some(path) = Self::config_path() else {
+            return Self::default();
+        };
+        let (config, _) = Self::load_from(&path);
+        config
    }

    pub fn save(&self) {
        if let Some(path) = Self::config_path() {
-            if let Some(dir) = path.parent() {
-                let _ = fs::create_dir_all(dir);
+            if let Err(e) = self.save_to(&path) {
+                crate::log_msg(&format!("config: save failed: {e:#}"));
            }
-            if let Ok(json) = serde_json::to_string_pretty(self) {
-                let _ = fs::write(path, json);
+        } else {
+            crate::log_msg("config: save failed: could not determine a config directory");
+        }
+    }
+
+    pub fn load_from(path: &Path) -> (Self, LoadOutcome) {
+        match fs::read_to_string(path) {
+            Ok(contents) => match serde_json::from_str(&contents) {
+                Ok(config) => (config, LoadOutcome::Loaded),
+                Err(e) => {
+                    let backup = recover_corrupt_config(path, &format!("failed to parse: {e}"));
+                    (Self::default(), backup)
+                }
+            },
+            Err(e) if e.kind() == std::io::ErrorKind::NotFound => {
+                (Self::default(), LoadOutcome::Missing)
+            }
+            Err(e) => {
+                let backup = recover_corrupt_config(path, &format!("failed to read: {e}"));
+                (Self::default(), backup)
            }
        }
    }
+
+    pub fn save_to(&self, path: &Path) -> anyhow::Result<()> {
+        let parent = path
+            .parent()
+            .context("config path has no parent directory")?;
+        fs::create_dir_all(parent)
+            .with_context(|| format!("failed to create {}", parent.display()))?;
+
+        let json = serde_json::to_string_pretty(self).context("failed to encode config")?;
+        let tmp = config_tmp_path(path)?;
+        let result = (|| -> anyhow::Result<()> {
+            {
+                let mut f = fs::File::create(&tmp)
+                    .with_context(|| format!("failed to create {}", tmp.display()))?;
+                f.write_all(json.as_bytes())
+                    .with_context(|| format!("failed to write {}", tmp.display()))?;
+                f.sync_all().ok();
+            }
+            fs::rename(&tmp, path).with_context(|| {
+                format!("failed to rename {} -> {}", tmp.display(), path.display())
+            })?;
+            Ok(())
+        })();
+
+        if result.is_err() {
+            let _ = fs::remove_file(&tmp);
+        }
+        result
+    }
+}
+
+fn config_tmp_path(path: &Path) -> anyhow::Result<PathBuf> {
+    let parent = path
+        .parent()
+        .context("config path has no parent directory")?;
+    let mut name = path
+        .file_name()
+        .context("config path has no file name")?
+        .to_os_string();
+    name.push(format!(".tmp.{}", std::process::id()));
+    Ok(parent.join(name))
+}
+
+fn corrupt_backup_path(path: &Path) -> PathBuf {
+    let secs = SystemTime::now()
+        .duration_since(UNIX_EPOCH)
+        .map(|d| d.as_secs())
+        .unwrap_or(0);
+    let parent = path.parent().unwrap_or_else(|| Path::new("."));
+    let mut name = path
+        .file_name()
+        .map(|n| n.to_os_string())
+        .unwrap_or_else(|| "config.json".into());
+    name.push(format!(".corrupt.{secs}"));
+    parent.join(name)
+}
+
+fn recover_corrupt_config(path: &Path, reason: &str) -> LoadOutcome {
+    let backup = corrupt_backup_path(path);
+    match fs::rename(path, &backup) {
+        Ok(()) => {
+            crate::log_msg(&format!(
+                "config: {reason}; moved damaged config to {}",
+                backup.display()
+            ));
+        }
+        Err(e) => {
+            crate::log_msg(&format!(
+                "config: {reason}; failed to move damaged config to {}: {e}",
+                backup.display()
+            ));
+        }
+    }
+    LoadOutcome::Recovered
 }

 #[cfg(test)]
@@ -456,14 +813,109 @@ mod tests {
        assert_eq!(original, deserialized);
    }

+    fn temp_config_path(tag: &str) -> PathBuf {
+        let mut p = std::env::temp_dir();
+        p.push(format!(
+            "peerspeak-configtest-{}-{}",
+            std::process::id(),
+            tag
+        ));
+        p.push("config.json");
+        p
+    }
+
+    #[test]
+    fn save_to_then_load_from_round_trips() {
+        let path = temp_config_path("roundtrip");
+        let _ = fs::remove_dir_all(path.parent().unwrap());
+        let cfg = AppConfig {
+            username: "Ada".into(),
+            input_device: "mic".into(),
+            output_device: "speaker".into(),
+            noise_gate_threshold: 0.42,
+            ..AppConfig::default()
+        };
+
+        cfg.save_to(&path).unwrap();
+        let (loaded, outcome) = AppConfig::load_from(&path);
+
+        assert_eq!(outcome, LoadOutcome::Loaded);
+        assert_eq!(loaded, cfg);
+        let _ = fs::remove_dir_all(path.parent().unwrap());
+    }
+
+    #[test]
+    fn load_from_missing_returns_default_without_corrupt_backup() {
+        let path = temp_config_path("missing");
+        let _ = fs::remove_dir_all(path.parent().unwrap());
+
+        let (loaded, outcome) = AppConfig::load_from(&path);
+
+        assert_eq!(outcome, LoadOutcome::Missing);
+        assert_eq!(loaded, AppConfig::default());
+        assert!(!path.parent().unwrap().exists());
+    }
+
+    #[test]
+    fn load_from_corrupt_file_preserves_original_bytes() {
+        let path = temp_config_path("corrupt");
+        let _ = fs::remove_dir_all(path.parent().unwrap());
+        fs::create_dir_all(path.parent().unwrap()).unwrap();
+        let corrupt = b"{ this is not json";
+        fs::write(&path, corrupt).unwrap();
+
+        let (loaded, outcome) = AppConfig::load_from(&path);
+
+        assert_eq!(outcome, LoadOutcome::Recovered);
+        assert_eq!(loaded, AppConfig::default());
+        assert_ne!(fs::read(&path).ok().as_deref(), Some(corrupt.as_slice()));
+        let backups: Vec<_> = fs::read_dir(path.parent().unwrap())
+            .unwrap()
+            .map(|entry| entry.unwrap().path())
+            .filter(|entry| {
+                entry
+                    .file_name()
+                    .and_then(|name| name.to_str())
+                    .is_some_and(|name| name.starts_with("config.json.corrupt."))
+            })
+            .collect();
+        assert_eq!(backups.len(), 1, "expected one corrupt backup");
+        assert_eq!(fs::read(&backups[0]).unwrap(), corrupt);
+        let _ = fs::remove_dir_all(path.parent().unwrap());
+    }
+
+    #[test]
+    fn save_to_leaves_no_tmp_file_after_success() {
+        let path = temp_config_path("atomic");
+        let _ = fs::remove_dir_all(path.parent().unwrap());
+
+        AppConfig::default().save_to(&path).unwrap();
+
+        let tmp_files: Vec<_> = fs::read_dir(path.parent().unwrap())
+            .unwrap()
+            .map(|entry| entry.unwrap().path())
+            .filter(|entry| {
+                entry
+                    .file_name()
+                    .and_then(|name| name.to_str())
+                    .is_some_and(|name| name.contains(".tmp."))
+            })
+            .collect();
+        assert!(tmp_files.is_empty(), "leftover temp files: {tmp_files:?}");
+        let _ = fs::remove_dir_all(path.parent().unwrap());
+    }
+
    #[test]
    fn test_backward_compat_default_fill() {
        let minimal_json = r#"{"input_device":"","output_device":"","noise_gate_threshold":0.01}"#;
        let deserialized: AppConfig = serde_json::from_str(minimal_json).unwrap();
-        
+
        assert_eq!(deserialized.network_mode, NetworkMode::RelayNoDiscovery);
        // Configs predating the presence posture load as friends-only (no beacon).
-        assert_eq!(deserialized.presence_mode, crate::presence::PresenceMode::Normal);
+        assert_eq!(
+            deserialized.presence_mode,
+            crate::presence::PresenceMode::Normal
+        );
        assert!(!deserialized.echo_cancellation_enabled);
        assert!(deserialized.notifications_enabled);
        // Configs predating the volume sliders must load at unity gain.
@@ -478,6 +930,8 @@ mod tests {
        assert_eq!(deserialized.room_layout, RoomLayout::BottomDock);
        assert_eq!(deserialized.controls_width, 280.0);
        assert_eq!(deserialized.chat_drawer_width, 320.0);
+        assert_eq!(deserialized.playlist_drawer_width, 320.0);
+        assert!(deserialized.show_player_bar);
        assert!(deserialized.custom_sound_self_join.is_none());
        assert!(deserialized.custom_sound_peer_join.is_none());
        assert!(deserialized.custom_sound_peer_leave.is_none());
@@ -486,10 +940,21 @@ mod tests {
        assert!(deserialized.custom_sound_self_leave.is_none());
        assert!(deserialized.custom_sound_mic_toggle.is_none());
        assert!(deserialized.custom_sound_reconnect_failed.is_none());
+        assert_eq!(deserialized.screen_share, ScreenShareSettings::default());
+        assert_eq!(deserialized.screen_share.quality, ShareQuality::Auto);
+        assert_eq!(deserialized.screen_share.player, SharePlayer::Mpv);
+        assert_eq!(
+            deserialized.screen_share.buffering,
+            ShareBuffering::LowLatency
+        );
+        assert_eq!(deserialized.screen_share.cache_mb, 2);
        // Configs predating the per-sound flags (W6) enable every chime, so an
        // upgrade is silent-change-free.
        for sound in Sound::ALL {
-            assert!(deserialized.sound_enabled(sound), "{sound:?} should default on");
+            assert!(
+                deserialized.sound_enabled(sound),
+                "{sound:?} should default on"
+            );
        }
        // The accessor and mutator agree round-trip.
        let mut cfg = AppConfig::default();
@@ -506,6 +971,7 @@ mod tests {
        assert!(deserialized.peer_eq.is_empty());
        assert!(deserialized.peer_pan.is_empty());
        assert!(deserialized.peer_volume.is_empty());
+        assert!(deserialized.music_source_volume.is_empty());
        assert!(deserialized.peer_gate.is_empty());
        assert_eq!(
            crate::hotkeys::format_binding(
@@ -535,7 +1001,10 @@ mod tests {
        }"#;
        let cfg: AppConfig = serde_json::from_str(legacy_json).unwrap();
        // The pre-existing single background survives untouched (still Option<String>).
-        assert_eq!(cfg.background.as_deref(), Some("/home/eric/.config/peerspeak/background.png"));
+        assert_eq!(
+            cfg.background.as_deref(),
+            Some("/home/eric/.config/peerspeak/background.png")
+        );
        assert!((cfg.background_dim - 0.4).abs() < f32::EPSILON);
        // The new game-detection fields default to off/empty → silent, opt-in upgrade.
        assert!(!cfg.game_presence_enabled);
@@ -547,9 +1016,12 @@ mod tests {
    fn test_game_maps_serialize_deterministically() {
        // BTreeMap ordering makes the serialized config stable across runs.
        let mut cfg = AppConfig::default();
-        cfg.game_backgrounds.insert("steam:730".into(), "/a.png".into());
-        cfg.game_backgrounds.insert("exe:hl2_linux".into(), "/b.png".into());
-        cfg.game_process_map.insert("hl2_linux".into(), "Half-Life 2".into());
+        cfg.game_backgrounds
+            .insert("steam:730".into(), "/a.png".into());
+        cfg.game_backgrounds
+            .insert("exe:hl2_linux".into(), "/b.png".into());
+        cfg.game_process_map
+            .insert("hl2_linux".into(), "Half-Life 2".into());
        let json = serde_json::to_string(&cfg).unwrap();
        // Keys appear in sorted order (exe: before steam:).
        let bg = json.find("game_backgrounds").unwrap();
@@ -607,8 +1079,7 @@ mod tests {
            recording_mode: RecordingMode::Both,
            ..AppConfig::default()
        };
-        let back: AppConfig =
-            serde_json::from_str(&serde_json::to_string(&cfg).unwrap()).unwrap();
+        let back: AppConfig = serde_json::from_str(&serde_json::to_string(&cfg).unwrap()).unwrap();
        assert_eq!(back.recording_mode, RecordingMode::Both);
        // is_multitrack() classifies correctly.
        assert!(!RecordingMode::Mixed.is_multitrack());
@@ -657,28 +1128,57 @@ mod tests {
        let def = AppConfig::default();
        assert_eq!(def.input_volume, 1.0);
        assert_eq!(def.output_volume, 1.0);
+        assert_eq!(def.clip_volume, 1.0);
+        assert!(def.music_playlist.is_empty());
+        assert_eq!(def.music_volume, 1.0);
+        assert!(!def.music_broadcast);
+        assert!(def.show_player_bar);
+        assert!(def.clip_volume_universal);

        // Missing in JSON → unity (serde default).
        let missing = r#"{"input_device":"","output_device":"","noise_gate_threshold":0.01}"#;
        let cfg_missing: AppConfig = serde_json::from_str(missing).unwrap();
        assert_eq!(cfg_missing.input_volume, 1.0);
        assert_eq!(cfg_missing.output_volume, 1.0);
+        assert_eq!(cfg_missing.clip_volume, 1.0);
+        assert!(cfg_missing.music_playlist.is_empty());
+        assert_eq!(cfg_missing.music_volume, 1.0);
+        assert!(!cfg_missing.music_broadcast);
+        assert!(cfg_missing.show_player_bar);
+        // Configs predating the toggle default to universal mode.
+        assert!(cfg_missing.clip_volume_universal);

        // Explicit non-unity values are preserved across a round-trip.
        let cfg = AppConfig {
            input_volume: 1.5,
            output_volume: 0.25,
+            clip_volume: 0.7,
+            music_playlist: vec!["/tmp/song.ogg".to_string()],
+            music_volume: 0.6,
+            music_broadcast: true,
+            show_player_bar: false,
+            clip_volume_universal: false,
            ..AppConfig::default()
        };
        let round_tripped: AppConfig =
            serde_json::from_str(&serde_json::to_string(&cfg).unwrap()).unwrap();
        assert_eq!(round_tripped.input_volume, 1.5);
        assert_eq!(round_tripped.output_volume, 0.25);
+        assert_eq!(round_tripped.clip_volume, 0.7);
+        assert_eq!(
+            round_tripped.music_playlist,
+            vec!["/tmp/song.ogg".to_string()]
+        );
+        assert_eq!(round_tripped.music_volume, 0.6);
+        assert!(round_tripped.music_broadcast);
+        assert!(!round_tripped.show_player_bar);
+        assert!(!round_tripped.clip_volume_universal);
    }

    #[test]
    fn test_notifications_enabled_specifically() {
-        let missing_notifications = r#"{"input_device":"","output_device":"","noise_gate_threshold":0.01}"#;
+        let missing_notifications =
+            r#"{"input_device":"","output_device":"","noise_gate_threshold":0.01}"#;
        let config_missing: AppConfig = serde_json::from_str(missing_notifications).unwrap();
        assert!(config_missing.notifications_enabled);

@@ -723,6 +1223,38 @@ mod tests {
        assert_ne!(display_0, display_2);
    }

+    #[test]
+    fn test_audio_profile() {
+        // Default is Balanced.
+        assert_eq!(AudioProfile::default(), AudioProfile::Balanced);
+
+        // ALL holds the three variants.
+        assert_eq!(AudioProfile::ALL.len(), 3);
+        assert!(AudioProfile::ALL.contains(&AudioProfile::LowLatency));
+        assert!(AudioProfile::ALL.contains(&AudioProfile::Balanced));
+        assert!(AudioProfile::ALL.contains(&AudioProfile::BadNetwork));
+
+        // as_u8 / from_u8 round-trip every variant, and unknown bytes fall back
+        // to the default rather than panicking.
+        for p in AudioProfile::ALL {
+            assert_eq!(AudioProfile::from_u8(p.as_u8()), p);
+        }
+        assert_eq!(AudioProfile::from_u8(99), AudioProfile::Balanced);
+
+        // serde round-trips, and Display strings are non-empty + distinct.
+        let mut labels = Vec::new();
+        for p in AudioProfile::ALL {
+            let s = serde_json::to_string(&p).unwrap();
+            assert_eq!(serde_json::from_str::<AudioProfile>(&s).unwrap(), p);
+            let label = p.to_string();
+            assert!(!label.is_empty());
+            labels.push(label);
+        }
+        labels.sort();
+        labels.dedup();
+        assert_eq!(labels.len(), 3);
+    }
+
    #[test]
    fn test_unknown_field_tolerance() {
        // Unknown/extra field tolerance: a config JSON containing an extra unrecognized key should still deserialize.
@@ -734,11 +1266,14 @@ mod tests {
            "unrecognized_field_xyz_123": "some_value"
        }"#;
        let deserialized_res: Result<AppConfig, _> = serde_json::from_str(json_with_extra);
-        
+
        // Assert that deserialization succeeds even with unrecognized/unknown fields.
        // This confirms that serde does not reject unknown fields (i.e. default behavior).
-        assert!(deserialized_res.is_ok(), "Config deserialization failed when an unknown field was present");
-        
+        assert!(
+            deserialized_res.is_ok(),
+            "Config deserialization failed when an unknown field was present"
+        );
+
        let config = deserialized_res.unwrap();
        assert_eq!(config.input_device, "");
        assert_eq!(config.output_device, "");
@@ -0,0 +1,187 @@
+//! Per-peer connection-transparency derivation.
+//!
+//! The transport hands us cumulative counters for each peer's selected QUIC
+//! path ([`PathSnapshot`]); this module turns two consecutive snapshots into
+//! the human-facing [`PeerConnInfo`] the UI renders (badge + tooltip): path
+//! type, RTT, and loss/bitrate over the poll window. Pure functions only —
+//! the polling task in `core::mod` owns the clock and the previous-snapshot
+//! map.
+
+use crate::network::PathSnapshot;
+use std::time::Duration;
+
+/// How often the core polls the transport for path snapshots.
+pub const POLL_INTERVAL: Duration = Duration::from_secs(1);
+
+/// Derived, display-ready connection info for one peer, sent to the UI via
+/// `UiEvent::ConnectionStats`. Window-relative fields are `None` when they
+/// can't be derived yet (first poll, path switch, or an idle window).
+#[derive(Debug, Clone, PartialEq)]
+pub struct PeerConnInfo {
+    /// True = relayed path, false = direct IP path.
+    pub relay: bool,
+    /// `ip:port` for a direct path, the relay URL for a relayed one.
+    pub remote_addr: String,
+    /// Path round-trip time, rounded to whole milliseconds.
+    pub rtt_ms: u32,
+    /// Percentage of packets sent in the window that were detected lost.
+    pub loss_pct: Option<f32>,
+    /// Outbound bitrate over the window, kilobits per second.
+    pub up_kbps: Option<f32>,
+    /// Inbound bitrate over the window, kilobits per second.
+    pub down_kbps: Option<f32>,
+}
+
+/// Derive display info from the current snapshot and (when comparable) the
+/// previous one. `prev` is comparable only if it's the same path — a relay→
+/// direct migration or a reconnect resets the counters, so those windows
+/// yield `None` rates rather than garbage (negative deltas show up as
+/// `cur < prev` and are treated the same way).
+pub fn derive(prev: Option<&PathSnapshot>, cur: &PathSnapshot, elapsed: Duration) -> PeerConnInfo {
+    let rates = prev
+        .filter(|p| comparable(p, cur))
+        .and_then(|p| window_rates(p, cur, elapsed));
+    PeerConnInfo {
+        relay: cur.is_relay,
+        remote_addr: cur.remote_addr.clone(),
+        rtt_ms: cur.rtt.as_millis().min(u128::from(u32::MAX)) as u32,
+        loss_pct: rates.and_then(|r| r.loss_pct),
+        up_kbps: rates.map(|r| r.up_kbps),
+        down_kbps: rates.map(|r| r.down_kbps),
+    }
+}
+
+/// True when `cur`'s counters continue `prev`'s: same path (address) and
+/// monotonically non-decreasing counters (a reconnect on the same address
+/// restarts them from zero).
+fn comparable(prev: &PathSnapshot, cur: &PathSnapshot) -> bool {
+    prev.remote_addr == cur.remote_addr
+        && cur.tx_bytes >= prev.tx_bytes
+        && cur.rx_bytes >= prev.rx_bytes
+        && cur.tx_datagrams >= prev.tx_datagrams
+        && cur.lost_packets >= prev.lost_packets
+}
+
+#[derive(Debug, Clone, Copy)]
+struct WindowRates {
+    loss_pct: Option<f32>,
+    up_kbps: f32,
+    down_kbps: f32,
+}
+
+fn window_rates(prev: &PathSnapshot, cur: &PathSnapshot, elapsed: Duration) -> Option<WindowRates> {
+    let secs = elapsed.as_secs_f64();
+    if secs <= 0.0 {
+        return None;
+    }
+    let sent = cur.tx_datagrams - prev.tx_datagrams;
+    let lost = cur.lost_packets - prev.lost_packets;
+    // Loss detection lags sending (it needs ACK timeouts), so a window can see
+    // more losses than sends; clamp to 100% rather than exceeding it. An idle
+    // window (nothing sent or lost) has no loss story to tell.
+    let loss_pct = if sent == 0 && lost == 0 {
+        None
+    } else {
+        Some(((lost as f64 / (sent.max(lost)) as f64) * 100.0) as f32)
+    };
+    let kbps = |bytes: u64| ((bytes as f64 * 8.0 / 1000.0) / secs) as f32;
+    Some(WindowRates {
+        loss_pct,
+        up_kbps: kbps(cur.tx_bytes - prev.tx_bytes),
+        down_kbps: kbps(cur.rx_bytes - prev.rx_bytes),
+    })
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn snap(addr: &str, tx_b: u64, rx_b: u64, tx_d: u64, lost: u64) -> PathSnapshot {
+        PathSnapshot {
+            is_relay: false,
+            remote_addr: addr.to_string(),
+            rtt: Duration::from_millis(12),
+            tx_bytes: tx_b,
+            rx_bytes: rx_b,
+            tx_datagrams: tx_d,
+            lost_packets: lost,
+        }
+    }
+
+    #[test]
+    fn first_poll_has_type_and_rtt_but_no_rates() {
+        let cur = snap("1.2.3.4:5", 1000, 2000, 50, 0);
+        let info = derive(None, &cur, POLL_INTERVAL);
+        assert_eq!(info.rtt_ms, 12);
+        assert!(!info.relay);
+        assert_eq!(info.remote_addr, "1.2.3.4:5");
+        assert_eq!(info.loss_pct, None);
+        assert_eq!(info.up_kbps, None);
+        assert_eq!(info.down_kbps, None);
+    }
+
+    #[test]
+    fn steady_window_yields_rates_and_loss() {
+        let prev = snap("1.2.3.4:5", 0, 0, 0, 0);
+        // 1s window: 4000 bytes up (32 kbps), 2000 down (16 kbps), 2 of 100 lost.
+        let cur = snap("1.2.3.4:5", 4000, 2000, 100, 2);
+        let info = derive(Some(&prev), &cur, Duration::from_secs(1));
+        assert_eq!(info.up_kbps, Some(32.0));
+        assert_eq!(info.down_kbps, Some(16.0));
+        assert_eq!(info.loss_pct, Some(2.0));
+    }
+
+    #[test]
+    fn idle_window_has_no_loss_story() {
+        let prev = snap("1.2.3.4:5", 4000, 2000, 100, 2);
+        let cur = prev.clone();
+        let info = derive(Some(&prev), &cur, Duration::from_secs(1));
+        assert_eq!(info.loss_pct, None);
+        assert_eq!(info.up_kbps, Some(0.0));
+    }
+
+    #[test]
+    fn loss_detected_in_an_idle_window_clamps_to_full() {
+        // Losses can be *detected* after sending stops (ACK timeouts fire late).
+        let prev = snap("1.2.3.4:5", 4000, 2000, 100, 0);
+        let cur = snap("1.2.3.4:5", 4000, 2000, 100, 3);
+        let info = derive(Some(&prev), &cur, Duration::from_secs(1));
+        assert_eq!(info.loss_pct, Some(100.0));
+    }
+
+    #[test]
+    fn path_switch_resets_the_window() {
+        let prev = snap("relay.example:443", 9000, 9000, 900, 5);
+        let cur = snap("1.2.3.4:5", 100, 100, 10, 0);
+        let info = derive(Some(&prev), &cur, Duration::from_secs(1));
+        assert_eq!(info.up_kbps, None);
+        assert_eq!(info.loss_pct, None);
+    }
+
+    #[test]
+    fn counter_reset_on_same_address_resets_the_window() {
+        // Same address but the connection was rebuilt → counters restarted.
+        let prev = snap("1.2.3.4:5", 9000, 9000, 900, 5);
+        let cur = snap("1.2.3.4:5", 100, 100, 10, 0);
+        let info = derive(Some(&prev), &cur, Duration::from_secs(1));
+        assert_eq!(info.up_kbps, None);
+        assert_eq!(info.loss_pct, None);
+    }
+
+    #[test]
+    fn zero_elapsed_yields_no_rates() {
+        let prev = snap("1.2.3.4:5", 0, 0, 0, 0);
+        let cur = snap("1.2.3.4:5", 4000, 2000, 100, 2);
+        let info = derive(Some(&prev), &cur, Duration::ZERO);
+        assert_eq!(info.up_kbps, None);
+        assert_eq!(info.loss_pct, None);
+    }
+
+    #[test]
+    fn oversized_rtt_saturates_instead_of_wrapping() {
+        let mut cur = snap("1.2.3.4:5", 0, 0, 0, 0);
+        cur.rtt = Duration::from_secs(u64::MAX);
+        let info = derive(None, &cur, POLL_INTERVAL);
+        assert_eq!(info.rtt_ms, u32::MAX);
+    }
+}
@@ -202,11 +202,15 @@ impl JitterBuffer {
                    None
                } else {
                    // Gap with later packets already buffered: a packet was lost
-                    // or reordered out of window. Conceal this frame via Opus PLC
-                    // and grow the cushion — the jitter beat our current delay.
+                    // or reordered out of window. First try Opus in-band FEC from
+                    // the next packet; if unavailable, fall back to plain PLC.
                    self.next_seq = Some(next.wrapping_add(1));
                    self.note_disruption();
-                    self.decoder.decode(None).ok()
+                    let next_payload = self.packets.values().next().expect("non-empty");
+                    self.decoder
+                        .decode_fec(next_payload)
+                        .or_else(|_| self.decoder.decode(None))
+                        .ok()
                }
            }
        }
@@ -221,8 +225,8 @@ impl JitterBuffer {
 #[cfg(test)]
 mod tests {
    use super::*;
-    use crate::codec::AudioEncoder;
-    use crate::codec::opus_impl::OpusEncoder;
+    use crate::codec::opus_impl::{OpusDecoder, OpusEncoder, OpusParams};
+    use crate::codec::{AudioDecoder, AudioEncoder};
    use opus::{Application, Channels};

    /// A real, decodable Opus packet for one 20ms mono frame at amplitude `amp`.
@@ -233,6 +237,32 @@ mod tests {
        enc.encode(&pcm).unwrap()
    }

+    fn tone_frame(enc: &mut OpusEncoder, amp: i16, frame_index: usize) -> Vec<u8> {
+        let pcm: Vec<i16> = (0..FRAME_SAMPLES)
+            .map(|i| {
+                let sample_index = frame_index * FRAME_SAMPLES + i;
+                let t = sample_index as f32 / 48_000.0;
+                let fundamental = (t * 220.0 * 2.0 * std::f32::consts::PI).sin();
+                let harmonic = (t * 440.0 * 2.0 * std::f32::consts::PI).sin();
+                ((fundamental * 0.7 + harmonic * 0.3) * amp as f32) as i16
+            })
+            .collect();
+        enc.encode(&pcm).unwrap()
+    }
+
+    fn rms_error(a: &[i16], b: &[i16]) -> f64 {
+        assert_eq!(a.len(), b.len());
+        let sum_sq: f64 = a
+            .iter()
+            .zip(b)
+            .map(|(&left, &right)| {
+                let diff = left as f64 - right as f64;
+                diff * diff
+            })
+            .sum();
+        (sum_sq / a.len() as f64).sqrt()
+    }
+
    #[test]
    fn buffers_then_plays_in_order() {
        let mut enc = OpusEncoder::new(48000, Channels::Mono, Application::Voip).unwrap();
@@ -289,6 +319,66 @@ mod tests {
        assert!(jb.pop_frame().is_none());
    }

+    #[test]
+    fn uses_in_band_fec_from_next_packet_for_gap() {
+        let mut enc = OpusEncoder::new(48000, Channels::Mono, Application::Voip).unwrap();
+        enc.apply_params(&OpusParams {
+            bitrate: 20_000,
+            inband_fec: true,
+            packet_loss_perc: 60,
+            dtx: false,
+        })
+        .unwrap();
+
+        let dropped_seq = 5usize;
+        let amps = [1800, 1800, 1800, 1800, 1800, 12_000, 12_000, 12_000];
+        let packets: Vec<Vec<u8>> = amps
+            .into_iter()
+            .enumerate()
+            .map(|(seq, amp)| tone_frame(&mut enc, amp, seq))
+            .collect();
+
+        let mut expected_decoder = OpusDecoder::new(48000, Channels::Mono, FRAME_SAMPLES).unwrap();
+        for packet in packets.iter().take(dropped_seq) {
+            expected_decoder.decode(Some(packet)).unwrap();
+        }
+        let expected_lost = expected_decoder
+            .decode(Some(&packets[dropped_seq]))
+            .unwrap();
+
+        let mut plc_decoder = OpusDecoder::new(48000, Channels::Mono, FRAME_SAMPLES).unwrap();
+        for packet in packets.iter().take(dropped_seq) {
+            plc_decoder.decode(Some(packet)).unwrap();
+        }
+        let pure_plc = plc_decoder.decode(None).unwrap();
+
+        let mut jb = JitterBuffer::new().unwrap();
+        for (seq, packet) in packets.iter().enumerate() {
+            if seq != dropped_seq {
+                jb.insert(seq as u32, packet.clone());
+            }
+        }
+
+        for _ in 0..dropped_seq {
+            assert_eq!(jb.pop_frame().map(|frame| frame.len()), Some(FRAME_SAMPLES));
+        }
+
+        let recovered = jb.pop_frame().expect("gap should be reconstructed");
+        assert_eq!(recovered.len(), FRAME_SAMPLES);
+        assert!(
+            jb.packets.contains_key(&(dropped_seq as u32 + 1)),
+            "FEC source packet must remain buffered for normal decode"
+        );
+        assert_eq!(jb.pop_frame().map(|frame| frame.len()), Some(FRAME_SAMPLES));
+
+        let fec_error = rms_error(&recovered, &expected_lost);
+        let plc_error = rms_error(&pure_plc, &expected_lost);
+        assert!(
+            fec_error < plc_error * 0.75,
+            "FEC reconstruction should be materially closer than PLC (fec_error={fec_error}, plc_error={plc_error})"
+        );
+    }
+
    #[test]
    fn drops_packets_already_played() {
        let mut enc = OpusEncoder::new(48000, Channels::Mono, Application::Voip).unwrap();
@@ -1,4 +1,4 @@
-use crate::config::{NetworkMode, RecordingMode};
+use crate::config::{AudioProfile, NetworkMode, RecordingMode, ScreenShareSettings, ShareQuality};
 use crate::friends::Friend;
 use crate::network::PeerState;
 use crate::presence::{FriendPresence, PresenceMode};
@@ -9,7 +9,15 @@ pub enum CoreCommand {
    /// Join a room. `ticket` is "create" (or empty) to mint a fresh room, else a
    /// share ticket to join. `room_name` is the creator's chosen cosmetic label
    /// for a NEW room; it's ignored when joining (the label rides in the ticket).
-    Join { name: String, ticket: String, room_name: String, input_device: Option<String>, output_device: Option<String>, echo_cancellation: bool, avatar: crate::avatar::Avatar },
+    Join {
+        name: String,
+        ticket: String,
+        room_name: String,
+        input_device: Option<String>,
+        output_device: Option<String>,
+        echo_cancellation: bool,
+        avatar: crate::avatar::Avatar,
+    },
    Leave,
    /// Orderly app shutdown: finalize recordings, leave any active room, stop local
    /// audio/screen-share work, close the persistent network stack, then ack with
@@ -41,10 +49,17 @@ pub enum CoreCommand {
    /// Start/stop a standalone capture-only stream that reports the raw mic
    /// level via [`UiEvent::MicLevel`], for gate calibration outside a call.
    /// Ignored while a room session is active (the in-call meter covers that).
-    SetMicMonitor { enabled: bool, input_device: Option<String> },
+    SetMicMonitor {
+        enabled: bool,
+        input_device: Option<String>,
+    },
    /// Set the relay/discovery posture. Takes effect on the next room join,
    /// since the endpoint is (re)built then.
    SetNetworkMode(NetworkMode),
+    /// Set the Opus encoder / network-resilience profile (W12). Applies live to
+    /// the running capture encoder, and to the next call's encoder. Sent at
+    /// startup from config and whenever the user changes it.
+    SetAudioProfile(AudioProfile),
    /// Start/stop recording the call to a local WAV (your mic + the incoming
    /// mix). No-op start if already recording / not in a call.
    SetRecording(bool),
@@ -56,23 +71,66 @@ pub enum CoreCommand {
    /// Send a chat message carrying a file attachment. The app has already read +
    /// capped the file and built the descriptor; core makes the bytes available
    /// on the file plane and broadcasts the descriptor.
-    SendChatFile { text: String, attachment: crate::files::ChatAttachment, data: Vec<u8> },
+    SendChatFile {
+        text: String,
+        attachment: crate::files::ChatAttachment,
+        data: Vec<u8>,
+    },
    /// Fetch a received attachment's bytes from its sender over the file plane
    /// (used for on-demand file/chip downloads; images are auto-fetched on
    /// receipt). Replies with `AttachmentReady`/`AttachmentFailed`.
-    FetchAttachment { from: EndpointId, attachment: crate::files::ChatAttachment },
+    FetchAttachment {
+        from: EndpointId,
+        attachment: crate::files::ChatAttachment,
+    },
+    /// Register `data` as fetchable under `id` for room members (the current
+    /// broadcast track). Called once per track when broadcasting.
+    ServeMusicTrack {
+        id: crate::files::AttachmentId,
+        data: std::sync::Arc<Vec<u8>>,
+    },
+    /// Drop a music blob that is no longer current-or-next.
+    ForgetMusicTrack(crate::files::AttachmentId),
+    /// Set (or clear) our broadcast music timeline and re-announce presence.
+    SetMusicPresence(Option<crate::network::MusicPresence>),
+    /// Fetch a source peer's current track bytes after tuning into them.
+    FetchMusic {
+        from: EndpointId,
+        id: crate::files::AttachmentId,
+        size: u64,
+    },
+    /// Fetch a source peer's advertised next track bytes before it becomes current.
+    PrefetchMusic {
+        from: EndpointId,
+        id: crate::files::AttachmentId,
+        size: u64,
+    },
    /// Set the pixelpass binary location (config override, empty = use `$PATH`).
    /// Sent at startup so screen-share can resolve the binary.
    SetPixelpassPath(Option<String>),
+    /// Enumerate apps currently producing audio (for the screen-share audio
+    /// picker, A23). Replies with [`UiEvent::AudioAppsListed`]. Cheap shell-out;
+    /// safe to call each time the picker opens.
+    ListAudioApps,
    /// Start sharing our screen: spawn a pixelpass host and announce its ticket
    /// on our presence so the room can watch. No-op when not in a call.
-    StartScreenShare,
+    /// `audio_app` selects which app's audio to capture: `Some(name)` captures
+    /// only that app (avoiding the call-loopback echo, A23); `None` shares the
+    /// whole desktop audio (the legacy behavior).
+    StartScreenShare {
+        audio_app: Option<String>,
+        settings: ScreenShareSettings,
+        quality: ShareQuality,
+    },
    /// Stop sharing our screen: kill the pixelpass host and clear the presence
    /// ticket. No-op when not sharing.
    StopScreenShare,
    /// Watch a peer's screen share: spawn a pixelpass viewer for `ticket` and
    /// open it in a local player.
-    ViewShare(String),
+    ViewShare {
+        ticket: String,
+        settings: ScreenShareSettings,
+    },
    /// Mint a fresh persistent identity (W7), discarding the old one. Takes effect
    /// on the next room join (the endpoint is rebuilt then). The core replies with
    /// an updated [`UiEvent::IdentityStatus`].
@@ -80,11 +138,19 @@ pub enum CoreCommand {
    /// Add a friend (W7). Core owns the friends store: it mutates + persists it and
    /// replies with [`UiEvent::FriendsUpdated`]. `addr` seeds `last_addr` if known
    /// (e.g. added from a room). Idempotent — re-adding an existing id is a no-op.
-    AddFriend { id: EndpointId, name: String, addr: Option<EndpointAddr> },
+    AddFriend {
+        id: EndpointId,
+        name: String,
+        addr: Option<EndpointAddr>,
+    },
    /// Remove a friend by id (W7).
    RemoveFriend(EndpointId),
    /// Locally rename a friend (W7).
    RenameFriend(EndpointId, String),
+    /// Run an immediate presence-refresh pass over all friends (the manual
+    /// "Rescan" button). Same work the 60s scheduler does on each tick, on demand —
+    /// no waiting for the next interval. A no-op while Invisible.
+    RefreshFriends,
    /// Set our presence posture (W7). Gates the idle listener (answer friends-only /
    /// invisible) and the outbound ping scheduler (invisible = fully dark). Sent at
    /// startup from config and whenever the user changes it.
@@ -102,68 +168,363 @@ pub enum CoreCommand {
    SetGameProcessMap(std::collections::BTreeMap<String, String>),
 }

+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum DeliveryClass {
+    Reliable,
+    BestEffort,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub enum CoalesceKey {
+    InputVolume,
+    OutputVolume,
+    NoiseGate,
+    PeerVolume(EndpointId),
+    PeerPan(EndpointId),
+    PeerGate(EndpointId),
+    PeerEq(EndpointId),
+}
+
+/// Route a command by how bad it is to drop it. Discrete, human-paced user
+/// actions are Reliable (must land). The only high-frequency commands are the
+/// continuous audio sliders, where dropping intermediate values is harmless;
+/// those are BestEffort.
+pub fn delivery_class(cmd: &CoreCommand) -> DeliveryClass {
+    match cmd {
+        CoreCommand::SetPeerVolume(_, _)
+        | CoreCommand::SetPeerPan(_, _)
+        | CoreCommand::SetPeerGate(_, _)
+        | CoreCommand::SetPeerEq(_, _)
+        | CoreCommand::SetInputVolume(_)
+        | CoreCommand::SetOutputVolume(_)
+        | CoreCommand::SetNoiseGateThreshold(_) => DeliveryClass::BestEffort,
+
+        CoreCommand::Join {
+            name: _,
+            ticket: _,
+            room_name: _,
+            input_device: _,
+            output_device: _,
+            echo_cancellation: _,
+            avatar: _,
+        }
+        | CoreCommand::Leave
+        | CoreCommand::Shutdown
+        | CoreCommand::ToggleMute
+        | CoreCommand::SetAvatar(_)
+        | CoreCommand::ToggleDeafen
+        | CoreCommand::SetPttMode(_)
+        | CoreCommand::SetPttActive(_)
+        | CoreCommand::SetPeerMuted(_, _)
+        | CoreCommand::SetMicMonitor {
+            enabled: _,
+            input_device: _,
+        }
+        | CoreCommand::SetNetworkMode(_)
+        | CoreCommand::SetAudioProfile(_)
+        | CoreCommand::SetRecording(_)
+        | CoreCommand::SetRecordingMode(_)
+        | CoreCommand::SendChat(_)
+        | CoreCommand::SendChatFile {
+            text: _,
+            attachment: _,
+            data: _,
+        }
+        | CoreCommand::FetchAttachment {
+            from: _,
+            attachment: _,
+        }
+        | CoreCommand::ServeMusicTrack { id: _, data: _ }
+        | CoreCommand::ForgetMusicTrack(_)
+        | CoreCommand::SetMusicPresence(_)
+        | CoreCommand::FetchMusic {
+            from: _,
+            id: _,
+            size: _,
+        }
+        | CoreCommand::PrefetchMusic {
+            from: _,
+            id: _,
+            size: _,
+        }
+        | CoreCommand::SetPixelpassPath(_)
+        | CoreCommand::ListAudioApps
+        | CoreCommand::StartScreenShare {
+            audio_app: _,
+            settings: _,
+            quality: _,
+        }
+        | CoreCommand::StopScreenShare
+        | CoreCommand::ViewShare {
+            ticket: _,
+            settings: _,
+        }
+        | CoreCommand::RegenerateIdentity
+        | CoreCommand::AddFriend {
+            id: _,
+            name: _,
+            addr: _,
+        }
+        | CoreCommand::RemoveFriend(_)
+        | CoreCommand::RenameFriend(_, _)
+        | CoreCommand::RefreshFriends
+        | CoreCommand::SetPresenceMode(_)
+        | CoreCommand::SetGamePresenceEnabled(_)
+        | CoreCommand::SetGameOverride(_)
+        | CoreCommand::SetGameProcessMap(_) => DeliveryClass::Reliable,
+    }
+}
+
+/// Coalescing bucket for high-frequency continuous controls. A key exists
+/// exactly for [`DeliveryClass::BestEffort`] commands.
+pub fn coalesce_key(cmd: &CoreCommand) -> Option<CoalesceKey> {
+    match cmd {
+        CoreCommand::SetPeerVolume(peer_id, _) => Some(CoalesceKey::PeerVolume(*peer_id)),
+        CoreCommand::SetPeerPan(peer_id, _) => Some(CoalesceKey::PeerPan(*peer_id)),
+        CoreCommand::SetPeerGate(peer_id, _) => Some(CoalesceKey::PeerGate(*peer_id)),
+        CoreCommand::SetPeerEq(peer_id, _) => Some(CoalesceKey::PeerEq(*peer_id)),
+        CoreCommand::SetInputVolume(_) => Some(CoalesceKey::InputVolume),
+        CoreCommand::SetOutputVolume(_) => Some(CoalesceKey::OutputVolume),
+        CoreCommand::SetNoiseGateThreshold(_) => Some(CoalesceKey::NoiseGate),
+
+        CoreCommand::Join {
+            name: _,
+            ticket: _,
+            room_name: _,
+            input_device: _,
+            output_device: _,
+            echo_cancellation: _,
+            avatar: _,
+        }
+        | CoreCommand::Leave
+        | CoreCommand::Shutdown
+        | CoreCommand::ToggleMute
+        | CoreCommand::SetAvatar(_)
+        | CoreCommand::ToggleDeafen
+        | CoreCommand::SetPttMode(_)
+        | CoreCommand::SetPttActive(_)
+        | CoreCommand::SetPeerMuted(_, _)
+        | CoreCommand::SetMicMonitor {
+            enabled: _,
+            input_device: _,
+        }
+        | CoreCommand::SetNetworkMode(_)
+        | CoreCommand::SetAudioProfile(_)
+        | CoreCommand::SetRecording(_)
+        | CoreCommand::SetRecordingMode(_)
+        | CoreCommand::SendChat(_)
+        | CoreCommand::SendChatFile {
+            text: _,
+            attachment: _,
+            data: _,
+        }
+        | CoreCommand::FetchAttachment {
+            from: _,
+            attachment: _,
+        }
+        | CoreCommand::ServeMusicTrack { id: _, data: _ }
+        | CoreCommand::ForgetMusicTrack(_)
+        | CoreCommand::SetMusicPresence(_)
+        | CoreCommand::FetchMusic {
+            from: _,
+            id: _,
+            size: _,
+        }
+        | CoreCommand::PrefetchMusic {
+            from: _,
+            id: _,
+            size: _,
+        }
+        | CoreCommand::SetPixelpassPath(_)
+        | CoreCommand::ListAudioApps
+        | CoreCommand::StartScreenShare {
+            audio_app: _,
+            settings: _,
+            quality: _,
+        }
+        | CoreCommand::StopScreenShare
+        | CoreCommand::ViewShare {
+            ticket: _,
+            settings: _,
+        }
+        | CoreCommand::RegenerateIdentity
+        | CoreCommand::AddFriend {
+            id: _,
+            name: _,
+            addr: _,
+        }
+        | CoreCommand::RemoveFriend(_)
+        | CoreCommand::RenameFriend(_, _)
+        | CoreCommand::RefreshFriends
+        | CoreCommand::SetPresenceMode(_)
+        | CoreCommand::SetGamePresenceEnabled(_)
+        | CoreCommand::SetGameOverride(_)
+        | CoreCommand::SetGameProcessMap(_) => None,
+    }
+}
+
 #[derive(Debug, Clone)]
 pub enum UiEvent {
-    RoomJoined { ticket: String, self_id: String },
+    RoomJoined {
+        ticket: String,
+        self_id: String,
+    },
    RoomLeft,
    /// Clear room-scoped UI state after a failed in-call room switch, without a
    /// leave chime. The persistent identity remains unchanged.
    RoomReset,
-    PeerJoined { id: EndpointId, state: PeerState },
-    PeerLeft { id: EndpointId },
+    PeerJoined {
+        id: EndpointId,
+        state: PeerState,
+    },
+    PeerLeft {
+        id: EndpointId,
+    },
    /// The fixed reconnect grace expired and bounded background gossip recovery
    /// has started. This is non-terminal and must not play the failure chime.
-    PeerRecoveryStarted { id: EndpointId },
-    PeerConnectionFailed { id: EndpointId },
-    PeerUpdated { id: EndpointId, state: PeerState },
+    PeerRecoveryStarted {
+        id: EndpointId,
+    },
+    PeerConnectionFailed {
+        id: EndpointId,
+    },
+    PeerUpdated {
+        id: EndpointId,
+        state: PeerState,
+    },
    /// Audio link to a peer is being (re)established — show a connecting state.
-    PeerConnecting { id: EndpointId },
+    PeerConnecting {
+        id: EndpointId,
+    },
    /// Audio link to a peer is up and carrying audio.
-    PeerConnected { id: EndpointId },
+    PeerConnected {
+        id: EndpointId,
+    },
    AudioLevels(Vec<(EndpointId, f32)>),
+    /// Periodic per-peer connection transparency snapshot (~1/sec): path type
+    /// (direct/relay), RTT, and window loss/bitrate for every peer with a live
+    /// audio link. A FULL replacement each time — a peer absent from the list
+    /// has no live link right now, so its badge should disappear.
+    ConnectionStats(Vec<(EndpointId, crate::core::connstats::PeerConnInfo)>),
    /// Raw (pre-gate, pre-mute) normalized RMS of the local mic, `0.0..=1.0`,
    /// for the settings level meter. Throttled to ~10/sec.
    MicLevel(f32),
    /// Call recording started; carries the absolute WAV path being written.
-    RecordingStarted { path: String },
+    RecordingStarted {
+        path: String,
+    },
    /// Call recording stopped; carries the finished WAV path.
-    RecordingStopped { path: String },
+    RecordingStopped {
+        path: String,
+    },
    /// A room text-chat message arrived from a peer (never our own — local
    /// messages are echoed by the UI on send). `from` is the sender's node id
    /// string, used to key their avatar (W4).
-    ChatMessage { from: String, name: String, text: String, attachment: Option<crate::files::ChatAttachment> },
+    ChatMessage {
+        from: String,
+        name: String,
+        text: String,
+        attachment: Option<crate::files::ChatAttachment>,
+    },
    /// An attachment's bytes are now available (auto-fetched for images, or
-    /// fetched on demand for files). Keyed by attachment id so the UI can match
-    /// it to the chat entry.
-    AttachmentReady { id: crate::files::AttachmentId, data: Vec<u8> },
+    /// fetched on demand for files). Keyed by `(from, id)`: the id is
+    /// attacker-chosen, so a malicious peer can reuse a victim's id — the author
+    /// disambiguates whose bytes these are and stops content aliasing (Tier C
+    /// F-12).
+    AttachmentReady {
+        from: EndpointId,
+        id: crate::files::AttachmentId,
+        data: Vec<u8>,
+    },
    /// An attachment fetch failed (sender gone, too large, decode error, etc.).
-    AttachmentFailed { id: crate::files::AttachmentId, error: String },
+    AttachmentFailed {
+        from: EndpointId,
+        id: crate::files::AttachmentId,
+        error: String,
+    },
+    /// A tuned-in source's track bytes arrived; play them in the music sink.
+    MusicReady {
+        from: EndpointId,
+        id: crate::files::AttachmentId,
+        data: Vec<u8>,
+    },
+    /// A tuned-in source's next-track bytes arrived; cache them for a gapless swap.
+    MusicPrefetched {
+        from: EndpointId,
+        id: crate::files::AttachmentId,
+        data: Vec<u8>,
+    },
+    /// A music-track fetch failed (source gone, too large, etc.).
+    MusicFetchFailed {
+        from: EndpointId,
+        id: crate::files::AttachmentId,
+        error: String,
+    },
+    /// The apps currently producing audio, for the screen-share audio picker
+    /// (A23). Sorted, deduplicated `application.name`s; empty when nothing is
+    /// playing or enumeration isn't available. `app_audio_supported` reports
+    /// whether the resolved pixelpass understands `--strict-audio`: when `false`
+    /// (an older pixelpass) the picker must offer whole-desktop audio only, since
+    /// a per-app share would pass a flag that older binary rejects (audit P2).
+    AudioAppsListed {
+        apps: Vec<String>,
+        app_audio_supported: bool,
+    },
    /// Our own screen share started; the UI flips the Share button to "Stop".
    ScreenShareStarted,
    /// Our own screen share stopped (or failed to start).
    ScreenShareStopped,
+    /// Per-app screen-share audio routing state (A23). `true` = the app we chose
+    /// is now reaching viewers; `false` = its audio stopped, so under our strict
+    /// run viewers currently hear silence. The UI shows a transient warning while
+    /// `false`. Only meaningful while sharing a specific app (not whole-desktop).
+    ShareAudioActive(bool),
+    /// A validly signed peer cannot be admitted because its gossip timestamp is
+    /// outside the replay freshness window. `peer_ahead` describes the peer's
+    /// sender-stamped timestamp relative to this machine's clock.
+    ClockSkewWarning {
+        skew_secs: u64,
+        peer_ahead: bool,
+    },
    /// Our node identity (W7): the current node id string, and whether it is
    /// PERSISTED to disk. Sent once at startup and again after a regenerate.
    /// `persisted = false` means the key file couldn't be read/written and we're
    /// running on an ephemeral fallback — a degraded state the UI must surface,
    /// since the id (and thus friend recognition) won't survive the next launch.
    /// `error` carries the reason when degraded, for the UI explainer.
-    IdentityStatus { node_id: String, persisted: bool, error: Option<String> },
+    IdentityStatus {
+        node_id: String,
+        persisted: bool,
+        error: Option<String>,
+    },
    /// The friends list (W7), now owned by core. Sent at startup (after load) and
    /// after every add/remove/rename so the GUI renders from this snapshot instead
    /// of owning the store. `read_only` is true when `friends.json` failed to load
    /// (malformed) — the GUI shows a degraded warning and disables edits so we never
    /// overwrite the damaged file (backlog A16).
-    FriendsUpdated { friends: Vec<Friend>, read_only: bool },
+    FriendsUpdated {
+        friends: Vec<Friend>,
+        read_only: bool,
+    },
    /// A friend's live presence from a successful ping reply (W7): online, or in a
    /// joinable gathering (with a one-click ticket). Emitted by the outbound ping
    /// scheduler; absence of a recent event = treat as offline.
-    FriendPresence { id: EndpointId, presence: FriendPresence },
+    FriendPresence {
+        id: EndpointId,
+        presence: FriendPresence,
+    },
+    /// A manual "Rescan" pass finished (every friend has been probed and its
+    /// per-friend `FriendPresence` already emitted). Lets the GUI clear the
+    /// transient "Rescanning…" status. Sent only for the on-demand button, not the
+    /// periodic auto-refresh, so the status bar isn't churned every interval.
+    FriendsRescanned,
    /// Core corrected the committed presence posture. Usually the Discoverable
    /// time-box elapsed and the core auto-reverted to `Normal`; on discovery apply
    /// failure, this carries the previous truthful mode. The GUI must mirror +
    /// persist this so its presence picker matches the endpoint's discovery state.
-    PresenceModeReverted { mode: PresenceMode },
+    PresenceModeReverted {
+        mode: PresenceMode,
+    },
    /// The locally-detected running game changed (game detection). Carries the
    /// debounced `DetectedGame` (id + display name + source) or `None` when nothing
    /// is detected. The GUI uses the stable `id` to switch the per-game background
@@ -174,3 +535,86 @@ pub enum UiEvent {
    ShutdownComplete,
    Error(String),
 }
+
+#[cfg(test)]
+mod tests {
+    use super::{CoalesceKey, CoreCommand, DeliveryClass, coalesce_key, delivery_class};
+    use crate::audio::eq::EqSettings;
+    use crate::presence::PresenceMode;
+    use iroh::{EndpointId, SecretKey};
+
+    fn endpoint_id() -> EndpointId {
+        SecretKey::generate().public()
+    }
+
+    #[test]
+    fn continuous_audio_controls_are_best_effort() {
+        let peer = endpoint_id();
+        let commands = [
+            (
+                CoreCommand::SetPeerVolume(peer, 0.7),
+                CoalesceKey::PeerVolume(peer),
+            ),
+            (
+                CoreCommand::SetPeerPan(peer, -0.2),
+                CoalesceKey::PeerPan(peer),
+            ),
+            (
+                CoreCommand::SetPeerGate(peer, 0.1),
+                CoalesceKey::PeerGate(peer),
+            ),
+            (
+                CoreCommand::SetPeerEq(peer, EqSettings::default()),
+                CoalesceKey::PeerEq(peer),
+            ),
+            (CoreCommand::SetInputVolume(0.8), CoalesceKey::InputVolume),
+            (CoreCommand::SetOutputVolume(0.9), CoalesceKey::OutputVolume),
+            (
+                CoreCommand::SetNoiseGateThreshold(0.02),
+                CoalesceKey::NoiseGate,
+            ),
+        ];
+
+        for (cmd, key) in commands {
+            assert_eq!(delivery_class(&cmd), DeliveryClass::BestEffort);
+            assert_eq!(coalesce_key(&cmd), Some(key));
+            assert_eq!(
+                coalesce_key(&cmd).is_some(),
+                delivery_class(&cmd) == DeliveryClass::BestEffort
+            );
+        }
+    }
+
+    #[test]
+    fn discrete_user_actions_are_reliable() {
+        let peer = endpoint_id();
+        let commands = [
+            CoreCommand::ToggleMute,
+            CoreCommand::SetPttActive(false),
+            CoreCommand::Leave,
+            CoreCommand::RegenerateIdentity,
+            CoreCommand::Join {
+                name: "Peer".to_string(),
+                ticket: "create".to_string(),
+                room_name: "Room".to_string(),
+                input_device: None,
+                output_device: None,
+                echo_cancellation: true,
+                avatar: crate::avatar::Avatar::default(),
+            },
+            CoreCommand::SetPeerMuted(peer, true),
+            CoreCommand::SetPresenceMode(PresenceMode::Normal),
+            CoreCommand::SetAudioProfile(crate::config::AudioProfile::BadNetwork),
+            CoreCommand::SendChat("hello".to_string()),
+        ];
+
+        for cmd in commands {
+            assert_eq!(delivery_class(&cmd), DeliveryClass::Reliable);
+            assert_eq!(coalesce_key(&cmd), None);
+            assert_eq!(
+                coalesce_key(&cmd).is_some(),
+                delivery_class(&cmd) == DeliveryClass::BestEffort
+            );
+        }
+    }
+}
@@ -22,6 +22,27 @@ fn recovery_delay(attempt: usize) -> Duration {
    RECOVERY_DELAYS[attempt.min(RECOVERY_DELAYS.len() - 1)]
 }

+/// Terminal retry budget for background recovery. After this many failed attempts
+/// the coordinator gives up: it drops the entry, frees the active slot, and signals
+/// the event task to forget the retained address (Tier C recovery-identity cap).
+///
+/// With the [`RECOVERY_DELAYS`] backoff this is roughly seven minutes of dialing
+/// (1+2+4+8+15+30+60s, then 60s steps), far beyond any normal transient outage. A
+/// genuine peer returning after a longer outage still rejoins on its own via a
+/// gossip announce, so giving up only stops us from dialing a peer that is not
+/// coming back — it does not break legitimate reconnect-after-outage.
+const RECOVERY_TERMINAL_ATTEMPTS: usize = 12;
+
+/// Capacity of the terminal-eviction notification channel. Bounded; on the rare
+/// event of saturation the entry is still removed (the dial work stops) and only
+/// the retained-address forget is skipped, which the per-topic retain cap bounds.
+const RECOVERY_TERMINAL_CAPACITY: usize = 64;
+
+/// Whether `attempt` completed recoveries have exhausted the terminal budget.
+fn recovery_is_terminal(attempt: usize, max_attempts: usize) -> bool {
+    attempt >= max_attempts
+}
+
 enum RecoveryCommand {
    Start {
        peer_id: EndpointId,
@@ -60,19 +81,24 @@ pub(super) struct RecoveryCoordinator {
 }

 impl RecoveryCoordinator {
-    pub(super) fn spawn(room_state: Arc<IrohGossipState>) -> (Self, JoinHandle<()>) {
+    pub(super) fn spawn(
+        room_state: Arc<IrohGossipState>,
+    ) -> (Self, JoinHandle<()>, mpsc::Receiver<EndpointId>) {
        Self::spawn_inner(room_state)
    }

-    fn spawn_inner(room_state: Arc<dyn RecoveryRoom>) -> (Self, JoinHandle<()>) {
+    fn spawn_inner(
+        room_state: Arc<dyn RecoveryRoom>,
+    ) -> (Self, JoinHandle<()>, mpsc::Receiver<EndpointId>) {
        let (tx, rx) = mpsc::channel(RECOVERY_COMMAND_CAPACITY);
+        let (terminal_tx, terminal_rx) = mpsc::channel(RECOVERY_TERMINAL_CAPACITY);
        let active = Arc::new(Mutex::new(HashSet::new()));
        let handle = Self {
            tx,
            active: active.clone(),
        };
-        let task = tokio::spawn(run_coordinator(room_state, active, rx));
-        (handle, task)
+        let task = tokio::spawn(run_coordinator(room_state, active, rx, terminal_tx));
+        (handle, task, terminal_rx)
    }

    /// Reserve one recovery slot before grace-expiry teardown begins. Returns
@@ -116,6 +142,7 @@ async fn run_coordinator(
    room_state: Arc<dyn RecoveryRoom>,
    active: Arc<Mutex<HashSet<EndpointId>>>,
    mut rx: mpsc::Receiver<RecoveryCommand>,
+    terminal_tx: mpsc::Sender<EndpointId>,
 ) {
    let mut entries: HashMap<EndpointId, RecoveryEntry> = HashMap::new();

@@ -155,9 +182,24 @@ async fn run_coordinator(
                                    entries.remove(&peer_id);
                                    continue;
                                }
-                                if let Some(entry) = entries.get_mut(&peer_id) {
+                                // Advance the backoff, then check the terminal budget.
+                                // `attempt` counts completed attempts, so the delay
+                                // uses the current value before it is incremented.
+                                let terminal = if let Some(entry) = entries.get_mut(&peer_id) {
                                    entry.next_attempt = scheduled_at + recovery_delay(entry.attempt);
                                    entry.attempt = entry.attempt.saturating_add(1);
+                                    recovery_is_terminal(entry.attempt, RECOVERY_TERMINAL_ATTEMPTS)
+                                } else {
+                                    false
+                                };
+                                if terminal {
+                                    // Give up on a peer that has not returned within the
+                                    // budget: drop its entry, free the active slot, and
+                                    // signal the event task to forget its retained
+                                    // address so the per-topic retain table drains.
+                                    entries.remove(&peer_id);
+                                    active.lock().unwrap().remove(&peer_id);
+                                    let _ = terminal_tx.try_send(peer_id);
                                }
                            }
                        }
@@ -210,6 +252,23 @@ mod tests {
        assert_eq!(actual, vec![1, 2, 4, 8, 15, 30, 60, 60, 60, 60]);
    }

+    #[test]
+    fn recovery_budget_is_terminal_only_at_or_past_the_cap() {
+        assert!(!recovery_is_terminal(0, RECOVERY_TERMINAL_ATTEMPTS));
+        assert!(!recovery_is_terminal(
+            RECOVERY_TERMINAL_ATTEMPTS - 1,
+            RECOVERY_TERMINAL_ATTEMPTS
+        ));
+        assert!(recovery_is_terminal(
+            RECOVERY_TERMINAL_ATTEMPTS,
+            RECOVERY_TERMINAL_ATTEMPTS
+        ));
+        assert!(recovery_is_terminal(
+            RECOVERY_TERMINAL_ATTEMPTS + 5,
+            RECOVERY_TERMINAL_ATTEMPTS
+        ));
+    }
+
    #[test]
    fn recovery_slots_are_deduplicated_and_cancel_immediately() {
        let (tx, mut rx) = mpsc::channel(4);
@@ -244,9 +303,10 @@ mod tests {
    #[tokio::test]
    async fn coordinator_attempts_rebootstrap_immediately() {
        let (attempts_tx, mut attempts_rx) = mpsc::unbounded_channel();
-        let (coordinator, task) = RecoveryCoordinator::spawn_inner(Arc::new(RecordingRoom {
-            attempts: attempts_tx,
-        }));
+        let (coordinator, task, _terminal_rx) =
+            RecoveryCoordinator::spawn_inner(Arc::new(RecordingRoom {
+                attempts: attempts_tx,
+            }));
        let peer_id = SecretKey::generate().public();
        let addr = EndpointAddr::from(peer_id);

@@ -283,8 +283,14 @@ mod tests {
        let q = echo.len() / 4;
        let early = erle(&echo[..q], &cleaned[..q]);
        let late = erle(&echo[3 * q..], &cleaned[3 * q..]);
-        assert!(late > early + 10.0, "should improve markedly: early {early:.1} late {late:.1}");
-        assert!(late > 20.0, "converged ERLE should exceed 20 dB, got {late:.1}");
+        assert!(
+            late > early + 10.0,
+            "should improve markedly: early {early:.1} late {late:.1}"
+        );
+        assert!(
+            late > 20.0,
+            "converged ERLE should exceed 20 dB, got {late:.1}"
+        );
    }

    #[test]
@@ -307,7 +313,10 @@ mod tests {
        let mut aec = Nlms::new(128, 0.5, 1e-6);
        let out = aec.process(&silent_ref, &near);
        for (a, b) in near.iter().zip(&out) {
-            assert!((a - b).abs() < 1e-6, "near-end should pass through: {a} vs {b}");
+            assert!(
+                (a - b).abs() < 1e-6,
+                "near-end should pass through: {a} vs {b}"
+            );
        }
    }

@@ -341,14 +350,24 @@ mod tests {
        let mut late_hits = 0;
        for i in 0..far.len() {
            if dtd.update(far[i], mic[i]) {
-                if i < onset { early_hits += 1 } else { late_hits += 1 }
+                if i < onset {
+                    early_hits += 1
+                } else {
+                    late_hits += 1
+                }
            }
        }
        // Echo-only stretch should rarely trip; near-end stretch should trip a lot.
        let early_rate = early_hits as f32 / onset as f32;
        let late_rate = late_hits as f32 / (far.len() - onset) as f32;
-        assert!(early_rate < 0.10, "false-positive rate {early_rate:.2} too high");
-        assert!(late_rate > 0.50, "missed double-talk, rate only {late_rate:.2}");
+        assert!(
+            early_rate < 0.10,
+            "false-positive rate {early_rate:.2} too high"
+        );
+        assert!(
+            late_rate > 0.50,
+            "missed double-talk, rate only {late_rate:.2}"
+        );
    }

    #[test]
@@ -380,6 +399,9 @@ mod tests {
            erle_dtd > erle_no + 15.0,
            "DTD should hold the echo path: with {erle_dtd:.1} dB vs without {erle_no:.1} dB"
        );
-        assert!(erle_dtd > 15.0, "held filter should still cancel echo: {erle_dtd:.1} dB");
+        assert!(
+            erle_dtd > 15.0,
+            "held filter should still cancel echo: {erle_dtd:.1} dB"
+        );
    }
 }
@@ -115,7 +115,10 @@ mod tests {
        let path = EchoPath::synthetic(480, 480, 0.5, 99);
        let echo = path.apply(&far);
        let ratio = rms(&echo) / rms(&far);
-        assert!((0.3..0.7).contains(&ratio), "echo/far rms ratio {ratio} off target");
+        assert!(
+            (0.3..0.7).contains(&ratio),
+            "echo/far rms ratio {ratio} off target"
+        );
    }

    #[test]
@@ -141,7 +141,10 @@ mod tests {
        buf[0] = Complex::new(1.0, 0.0);
        fft(&mut buf);
        for c in &buf {
-            assert!(approx(c.magnitude(), 1.0, 1e-9), "expected flat 1.0, got {c:?}");
+            assert!(
+                approx(c.magnitude(), 1.0, 1e-9),
+                "expected flat 1.0, got {c:?}"
+            );
        }
    }

@@ -62,11 +62,31 @@ pub struct Band {

 /// Voice-relevant bands for spotting *where* residual echo or noise lives.
 pub const VOICE_BANDS: &[Band] = &[
-    Band { label: "low (80-300)", low_hz: 80.0, high_hz: 300.0 },
-    Band { label: "low-mid (300-1k)", low_hz: 300.0, high_hz: 1000.0 },
-    Band { label: "mid (1k-3k)", low_hz: 1000.0, high_hz: 3000.0 },
-    Band { label: "high-mid (3k-6k)", low_hz: 3000.0, high_hz: 6000.0 },
-    Band { label: "high (6k-12k)", low_hz: 6000.0, high_hz: 12000.0 },
+    Band {
+        label: "low (80-300)",
+        low_hz: 80.0,
+        high_hz: 300.0,
+    },
+    Band {
+        label: "low-mid (300-1k)",
+        low_hz: 300.0,
+        high_hz: 1000.0,
+    },
+    Band {
+        label: "mid (1k-3k)",
+        low_hz: 1000.0,
+        high_hz: 3000.0,
+    },
+    Band {
+        label: "high-mid (3k-6k)",
+        low_hz: 3000.0,
+        high_hz: 6000.0,
+    },
+    Band {
+        label: "high (6k-12k)",
+        low_hz: 6000.0,
+        high_hz: 12000.0,
+    },
 ];

 /// Sums the linear magnitude energy within `[low_hz, high_hz)` across a single
@@ -202,7 +202,8 @@ fn legend(opts: &RenderOpts) -> String {
    if opts.ascii {
        for i in 0..steps {
            let v = i as f32 / (steps - 1) as f32;
-            let idx = ((v * (ASCII_RAMP.len() - 1) as f32).round() as usize).min(ASCII_RAMP.len() - 1);
+            let idx =
+                ((v * (ASCII_RAMP.len() - 1) as f32).round() as usize).min(ASCII_RAMP.len() - 1);
            s.push(ASCII_RAMP[idx] as char);
        }
    } else {
@@ -243,7 +244,11 @@ mod tests {
    fn render_produces_grid_of_expected_height() {
        let sig = generators::sine(2000.0, 0.8, 48_000, 48_000);
        let spec = stft::analyze(&sig, 48_000, 1024, 512);
-        let opts = RenderOpts { width: 40, height: 10, ..Default::default() };
+        let opts = RenderOpts {
+            width: 40,
+            height: 10,
+            ..Default::default()
+        };
        let out = render(&spec, &opts);
        // Header + 10 body rows + time axis (2) + legend = non-trivial.
        let lines = out.lines().count();
@@ -94,7 +94,10 @@ mod tests {
            .unwrap()
            .0;
        let peak_hz = s.bin_hz(peak_bin);
-        assert!((peak_hz - freq as f32).abs() < 100.0, "peak at {peak_hz} Hz, want {freq}");
+        assert!(
+            (peak_hz - freq as f32).abs() < 100.0,
+            "peak at {peak_hz} Hz, want {freq}"
+        );
    }

    #[test]
@@ -34,7 +34,12 @@ pub fn read(path: &Path) -> Result<WavData, String> {
    let mut pos = 12usize;
    while pos + 8 <= bytes.len() {
        let id = &bytes[pos..pos + 4];
-        let size = u32::from_le_bytes([bytes[pos + 4], bytes[pos + 5], bytes[pos + 6], bytes[pos + 7]]) as usize;
+        let size = u32::from_le_bytes([
+            bytes[pos + 4],
+            bytes[pos + 5],
+            bytes[pos + 6],
+            bytes[pos + 7],
+        ]) as usize;
        let body_start = pos + 8;
        let body_end = (body_start + size).min(bytes.len());
        match id {
@@ -45,7 +50,9 @@ pub fn read(path: &Path) -> Result<WavData, String> {
                sample_rate = u32::from_le_bytes([fmt[4], fmt[5], fmt[6], fmt[7]]);
                bits = u16::from_le_bytes([fmt[14], fmt[15]]);
                if audio_format != 1 {
-                    return Err(format!("unsupported WAV format tag {audio_format} (need PCM=1)"));
+                    return Err(format!(
+                        "unsupported WAV format tag {audio_format} (need PCM=1)"
+                    ));
                }
            }
            b"data" => {
@@ -75,7 +82,10 @@ pub fn read(path: &Path) -> Result<WavData, String> {
        samples.push(avg / 32768.0);
    }

-    Ok(WavData { samples, sample_rate })
+    Ok(WavData {
+        samples,
+        sample_rate,
+    })
 }

 /// Writes mono `f32` samples (clamped to `[-1, 1]`) as a 16-bit PCM WAV. Used by
@@ -76,10 +76,7 @@ pub fn sanitize_filename(raw: &str) -> String {
        .trim();

    // Drop control chars; turn other whitespace into single spaces later.
-    let cleaned: String = base
-        .chars()
-        .filter(|c| !c.is_control())
-        .collect();
+    let cleaned: String = base.chars().filter(|c| !c.is_control()).collect();
    let collapsed = cleaned.split_whitespace().collect::<Vec<_>>().join(" ");
    let collapsed = collapsed.trim_matches('.').trim();

@@ -145,7 +142,10 @@ pub fn looks_like_audio_name(name: &str) -> bool {
    let Some((_, extension)) = name.rsplit_once('.') else {
        return false;
    };
-    matches!(extension.to_ascii_lowercase().as_str(), "wav" | "mp3" | "ogg" | "oga" | "flac")
+    matches!(
+        extension.to_ascii_lowercase().as_str(),
+        "wav" | "mp3" | "ogg" | "oga" | "flac"
+    )
 }

 /// The attachment kind for some file bytes: [`AttachmentKind::Image`] if it
@@ -240,7 +240,11 @@ mod tests {
        let long_stem = "x".repeat(200);
        let name = format!("{long_stem}.png");
        let out = sanitize_filename(&name);
-        assert!(out.chars().count() <= MAX_FILENAME_LEN, "len was {}", out.chars().count());
+        assert!(
+            out.chars().count() <= MAX_FILENAME_LEN,
+            "len was {}",
+            out.chars().count()
+        );
        assert!(out.ends_with(".png"), "extension preserved: {out}");
    }

@@ -254,7 +258,9 @@ mod tests {

    #[test]
    fn image_sniffing_recognizes_containers() {
-        assert!(is_probably_image(&[0x89, b'P', b'N', b'G', 0x0D, 0x0A, 0x1A, 0x0A, 0, 0]));
+        assert!(is_probably_image(&[
+            0x89, b'P', b'N', b'G', 0x0D, 0x0A, 0x1A, 0x0A, 0, 0
+        ]));
        assert!(is_probably_image(&[0xFF, 0xD8, 0xFF, 0xE0]));
        assert!(is_probably_image(b"GIF89a...."));
        let mut webp = b"RIFF".to_vec();
@@ -66,7 +66,11 @@ impl FriendStore {
        if self.contains(&id) {
            return false;
        }
-        self.friends.push(Friend { id, name, last_addr: addr });
+        self.friends.push(Friend {
+            id,
+            name,
+            last_addr: addr,
+        });
        true
    }

@@ -118,21 +122,24 @@ pub fn friends_path() -> Option<PathBuf> {
 /// *parse* error bubbles up so a hand-edit being debugged isn't silently
 /// overwritten with an empty list.
 pub fn load() -> Result<FriendStore> {
-    let path = friends_path().context("could not determine a config directory for the friends list")?;
+    let path =
+        friends_path().context("could not determine a config directory for the friends list")?;
    load_at(&path)
 }

 /// Save the store. Atomic via tempfile-in-same-dir + rename.
 pub fn save(store: &FriendStore) -> Result<()> {
-    let path = friends_path().context("could not determine a config directory for the friends list")?;
+    let path =
+        friends_path().context("could not determine a config directory for the friends list")?;
    save_at(&path, store)
 }

 /// Path-injectable core of [`load`], so the round-trip is testable in a temp dir.
 fn load_at(path: &Path) -> Result<FriendStore> {
    match fs::read_to_string(path) {
-        Ok(s) => serde_json::from_str(&s)
-            .with_context(|| format!("failed to parse {}", path.display())),
+        Ok(s) => {
+            serde_json::from_str(&s).with_context(|| format!("failed to parse {}", path.display()))
+        }
        Err(e) if e.kind() == std::io::ErrorKind::NotFound => Ok(FriendStore::default()),
        Err(e) => Err(e).with_context(|| format!("failed to read {}", path.display())),
    }
@@ -141,11 +148,14 @@ fn load_at(path: &Path) -> Result<FriendStore> {
 /// Path-injectable core of [`save`]. Atomic write: tempfile-in-same-dir, then
 /// rename, so a crash mid-write can't leave a truncated list.
 fn save_at(path: &Path, store: &FriendStore) -> Result<()> {
-    let parent = path.parent().context("friends path has no parent directory")?;
+    let parent = path
+        .parent()
+        .context("friends path has no parent directory")?;
    fs::create_dir_all(parent).with_context(|| format!("failed to create {}", parent.display()))?;
    let json = serde_json::to_string_pretty(store).context("failed to encode the friends list")?;
    let tmp = parent.join(format!(".friends.json.tmp.{}", std::process::id()));
-    fs::write(&tmp, json.as_bytes()).with_context(|| format!("failed to write {}", tmp.display()))?;
+    fs::write(&tmp, json.as_bytes())
+        .with_context(|| format!("failed to write {}", tmp.display()))?;
    fs::rename(&tmp, path)
        .with_context(|| format!("failed to rename {} -> {}", tmp.display(), path.display()))?;
    Ok(())
@@ -219,7 +229,11 @@ mod tests {
    /// A unique temp path; `save_at` creates the nested dir (exercises create_dir_all).
    fn temp_path(tag: &str) -> PathBuf {
        let mut p = std::env::temp_dir();
-        p.push(format!("peerspeak-friendstest-{}-{}", std::process::id(), tag));
+        p.push(format!(
+            "peerspeak-friendstest-{}-{}",
+            std::process::id(),
+            tag
+        ));
        p.push("friends.json");
        p
    }
@@ -9,11 +9,9 @@
 //! is factored into the pure [`poll_once`] so the wiring of resolve + match +
 //! debounce is unit-tested without any I/O.

-use super::{
-    builtin_denylist, match_processes, resolve, Debouncer, DetectedGame, ManualOverride,
-};
 use super::scan;
 use super::steam::SteamProbe;
+use super::{Debouncer, DetectedGame, ManualOverride, builtin_denylist, match_processes, resolve};
 use std::collections::BTreeMap;
 use std::io;
 use std::sync::atomic::{AtomicBool, Ordering};
@@ -145,9 +143,14 @@ fn worker_loop(
        let steam_game = steam.detect();
        let processes = scan::running_executables();

-        if let Some(new_current) =
-            poll_once(&mut debouncer, &override_, steam_game, &processes, &process_map, &denylist)
-        {
+        if let Some(new_current) = poll_once(
+            &mut debouncer,
+            &override_,
+            steam_game,
+            &processes,
+            &process_map,
+            &denylist,
+        ) {
            // A closed receiver means core shut down; stop quietly.
            if tx.send(new_current).is_err() {
                return;
@@ -169,11 +172,18 @@ mod tests {
    use super::*;

    fn game(id: &str, name: &str, source: GameSource) -> DetectedGame {
-        DetectedGame { id: id.into(), name: Some(name.into()), source }
+        DetectedGame {
+            id: id.into(),
+            name: Some(name.into()),
+            source,
+        }
    }

    fn map(pairs: &[(&str, &str)]) -> BTreeMap<String, String> {
-        pairs.iter().map(|(k, v)| (k.to_string(), v.to_string())).collect()
+        pairs
+            .iter()
+            .map(|(k, v)| (k.to_string(), v.to_string()))
+            .collect()
    }

    #[test]
@@ -185,17 +195,38 @@ mod tests {

        // First poll: detected but not yet published (needs two hits).
        assert_eq!(
-            poll_once(&mut d, &ManualOverride::Auto, Some(steam.clone()), &[], &empty, &deny),
+            poll_once(
+                &mut d,
+                &ManualOverride::Auto,
+                Some(steam.clone()),
+                &[],
+                &empty,
+                &deny
+            ),
            None
        );
        // Second poll: published.
        assert_eq!(
-            poll_once(&mut d, &ManualOverride::Auto, Some(steam.clone()), &[], &empty, &deny),
+            poll_once(
+                &mut d,
+                &ManualOverride::Auto,
+                Some(steam.clone()),
+                &[],
+                &empty,
+                &deny
+            ),
            Some(Some(steam))
        );
        // Third identical poll: no change event.
        assert_eq!(
-            poll_once(&mut d, &ManualOverride::Auto, Some(game("steam:730", "CS2", GameSource::Steam)), &[], &empty, &deny),
+            poll_once(
+                &mut d,
+                &ManualOverride::Auto,
+                Some(game("steam:730", "CS2", GameSource::Steam)),
+                &[],
+                &empty,
+                &deny
+            ),
            None
        );
    }
@@ -209,7 +240,9 @@ mod tests {

        poll_once(&mut d, &ManualOverride::Auto, None, &procs, &user, &deny);
        let change = poll_once(&mut d, &ManualOverride::Auto, None, &procs, &user, &deny);
-        let published = change.expect("should publish on second hit").expect("a game");
+        let published = change
+            .expect("should publish on second hit")
+            .expect("a game");
        assert_eq!(published.id, "exe:hl2_linux");
        assert_eq!(published.name.as_deref(), Some("Half-Life 2"));
    }
@@ -92,11 +92,20 @@ pub fn resolve(
    processes: &[DetectedGame],
 ) -> Resolution {
    match override_ {
-        ManualOverride::ForceNone => Resolution { game: None, immediate: true },
-        ManualOverride::Force(g) => Resolution { game: Some(g.clone()), immediate: true },
+        ManualOverride::ForceNone => Resolution {
+            game: None,
+            immediate: true,
+        },
+        ManualOverride::Force(g) => Resolution {
+            game: Some(g.clone()),
+            immediate: true,
+        },
        ManualOverride::Auto => {
            let game = steam.or_else(|| processes.first().cloned());
-            Resolution { game, immediate: false }
+            Resolution {
+                game,
+                immediate: false,
+            }
        }
    }
 }
@@ -192,7 +201,11 @@ impl Debouncer {
 /// lowercase it. Keeps any extension (`minecraft.exe` stays distinct from a
 /// hypothetical `minecraft`), trims surrounding whitespace.
 pub fn normalize_exe(raw: &str) -> String {
-    raw.rsplit(['/', '\\']).next().unwrap_or(raw).trim().to_lowercase()
+    raw.rsplit(['/', '\\'])
+        .next()
+        .unwrap_or(raw)
+        .trim()
+        .to_lowercase()
 }

 /// Launcher/helper executables that must NEVER be reported as a game even if a
@@ -245,8 +258,10 @@ pub fn match_processes(
    denylist: &BTreeSet<&str>,
 ) -> Vec<DetectedGame> {
    // Normalize the user map once so lookups are basename/case-insensitive.
-    let normalized_map: BTreeMap<String, &String> =
-        user_map.iter().map(|(k, v)| (normalize_exe(k), v)).collect();
+    let normalized_map: BTreeMap<String, &String> = user_map
+        .iter()
+        .map(|(k, v)| (normalize_exe(k), v))
+        .collect();

    let mut seen: BTreeSet<String> = BTreeSet::new();
    let mut out: Vec<DetectedGame> = Vec::new();
@@ -288,8 +303,14 @@ mod tests {
    #[test]
    fn stable_ids_are_namespaced() {
        assert_eq!(DetectedGame::steam_id(730), "steam:730");
-        assert_eq!(DetectedGame::exe_id("/usr/games/hl2_linux"), "exe:hl2_linux");
-        assert_eq!(DetectedGame::exe_id("C:\\Games\\Minecraft.exe"), "exe:minecraft.exe");
+        assert_eq!(
+            DetectedGame::exe_id("/usr/games/hl2_linux"),
+            "exe:hl2_linux"
+        );
+        assert_eq!(
+            DetectedGame::exe_id("C:\\Games\\Minecraft.exe"),
+            "exe:minecraft.exe"
+        );
    }

    #[test]
@@ -318,8 +339,16 @@ mod tests {
    #[test]
    fn resolve_falls_back_to_first_process_then_none() {
        let procs = vec![
-            DetectedGame { id: "exe:a".into(), name: Some("A".into()), source: GameSource::Process },
-            DetectedGame { id: "exe:b".into(), name: Some("B".into()), source: GameSource::Process },
+            DetectedGame {
+                id: "exe:a".into(),
+                name: Some("A".into()),
+                source: GameSource::Process,
+            },
+            DetectedGame {
+                id: "exe:b".into(),
+                name: Some("B".into()),
+                source: GameSource::Process,
+            },
        ];
        let r = resolve(&ManualOverride::Auto, None, &procs);
        assert_eq!(r.game.as_ref().unwrap().id, "exe:a");
@@ -426,7 +455,10 @@ mod tests {
    // --- process matching --------------------------------------------------

    fn map(pairs: &[(&str, &str)]) -> BTreeMap<String, String> {
-        pairs.iter().map(|(k, v)| (k.to_string(), v.to_string())).collect()
+        pairs
+            .iter()
+            .map(|(k, v)| (k.to_string(), v.to_string()))
+            .collect()
    }

    #[test]
@@ -461,14 +493,13 @@ mod tests {
        let user = map(&[("zed", "Zed"), ("alpha", "Alpha")]);
        let deny = builtin_denylist();
        // Same game twice (two processes) + reverse discovery order.
-        let running = vec![
-            "/b/zed".into(),
-            "/a/alpha".into(),
-            "/c/alpha".into(),
-        ];
+        let running = vec!["/b/zed".into(), "/a/alpha".into(), "/c/alpha".into()];
        let got = match_processes(&running, &user, &deny);
        // Deduped to two, sorted by id (alpha before zed) regardless of scan order.
-        assert_eq!(got.iter().map(|g| g.id.as_str()).collect::<Vec<_>>(), vec!["exe:alpha", "exe:zed"]);
+        assert_eq!(
+            got.iter().map(|g| g.id.as_str()).collect::<Vec<_>>(),
+            vec!["exe:alpha", "exe:zed"]
+        );
    }

    #[test]
@@ -62,7 +62,7 @@ fn linux_proc_executables() -> Vec<String> {
 fn windows_toolhelp_executables() -> Vec<String> {
    use windows_sys::Win32::Foundation::{CloseHandle, INVALID_HANDLE_VALUE};
    use windows_sys::Win32::System::Diagnostics::ToolHelp::{
-        CreateToolhelp32Snapshot, Process32FirstW, Process32NextW, PROCESSENTRY32W,
+        CreateToolhelp32Snapshot, PROCESSENTRY32W, Process32FirstW, Process32NextW,
        TH32CS_SNAPPROCESS,
    };

@@ -78,7 +78,11 @@ fn windows_toolhelp_executables() -> Vec<String> {
    let mut ok = unsafe { Process32FirstW(snapshot, &mut entry) };
    while ok != 0 {
        // szExeFile is a NUL-terminated UTF-16 array (the basename, e.g. game.exe).
-        let end = entry.szExeFile.iter().position(|&c| c == 0).unwrap_or(entry.szExeFile.len());
+        let end = entry
+            .szExeFile
+            .iter()
+            .position(|&c| c == 0)
+            .unwrap_or(entry.szExeFile.len());
        let name = String::from_utf16_lossy(&entry.szExeFile[..end]);
        if !name.is_empty() {
            out.push(name);
@@ -93,15 +97,16 @@ fn windows_toolhelp_executables() -> Vec<String> {

 #[cfg(test)]
 mod tests {
-    use super::*;
-
    #[cfg(target_os = "linux")]
    #[test]
    fn enumerates_at_least_this_process() {
        // The test runner itself is a process, so /proc enumeration must be
        // non-empty and include something that normalizes to our own exe basename.
-        let exes = running_executables();
-        assert!(!exes.is_empty(), "expected to see running processes via /proc");
+        let exes = super::running_executables();
+        assert!(
+            !exes.is_empty(),
+            "expected to see running processes via /proc"
+        );
        // Our own /proc/self/exe basename should appear among them.
        let me = std::fs::read_link("/proc/self/exe")
            .ok()
@@ -109,7 +114,8 @@ mod tests {
        if let Some(me) = me {
            let me_norm = super::super::normalize_exe(&me);
            assert!(
-                exes.iter().any(|e| super::super::normalize_exe(e) == me_norm),
+                exes.iter()
+                    .any(|e| super::super::normalize_exe(e) == me_norm),
                "running list should include our own executable {me_norm:?}"
            );
        }
@@ -25,8 +25,7 @@ const MAX_STEAM_PATH_BYTES: u32 = 4 * 1024;

 #[cfg(any(windows, test))]
 fn validate_reg_len(len: u32) -> Option<usize> {
-    (len != 0 && len.is_multiple_of(2) && len <= MAX_STEAM_PATH_BYTES)
-        .then_some(len as usize / 2)
+    (len != 0 && len.is_multiple_of(2) && len <= MAX_STEAM_PATH_BYTES).then_some(len as usize / 2)
 }

 #[cfg(any(windows, test))]
@@ -48,7 +47,14 @@ fn decode_reg_sz(mut buf: Vec<u16>, returned_bytes: u32) -> Option<String> {
 pub fn parse_running_app_id(registry_vdf: &str) -> Option<u32> {
    let root = vdf::parse(registry_vdf).ok()?;
    let raw = root
-        .get_path(&["Registry", "HKCU", "Software", "Valve", "Steam", "RunningAppID"])
+        .get_path(&[
+            "Registry",
+            "HKCU",
+            "Software",
+            "Valve",
+            "Steam",
+            "RunningAppID",
+        ])
        .and_then(Value::as_str)?;
    let id: u32 = raw.trim().parse().ok()?;
    (id != 0).then_some(id)
@@ -196,7 +202,13 @@ impl SteamProbe {
            return cached.name.clone();
        }
        let name = read_capped(&manifest).and_then(|c| parse_app_name(&c));
-        self.manifests.insert(app_id, CachedManifest { mtime, name: name.clone() });
+        self.manifests.insert(
+            app_id,
+            CachedManifest {
+                mtime,
+                name: name.clone(),
+            },
+        );
        name
    }

@@ -240,7 +252,11 @@ impl SteamProbe {
                paths.push(root.clone());
            }
        }
-        self.libraries = CachedLibraries { source, mtime, paths: paths.clone() };
+        self.libraries = CachedLibraries {
+            source,
+            mtime,
+            paths: paths.clone(),
+        };
        paths
    }
 }
@@ -360,8 +376,8 @@ mod win {
    use std::path::PathBuf;
    use windows_sys::Win32::Foundation::ERROR_SUCCESS;
    use windows_sys::Win32::System::Registry::{
-        RegCloseKey, RegOpenKeyExW, RegQueryValueExW, HKEY, HKEY_CURRENT_USER, KEY_READ,
-        REG_DWORD, REG_SZ,
+        HKEY, HKEY_CURRENT_USER, KEY_READ, REG_DWORD, REG_SZ, RegCloseKey, RegOpenKeyExW,
+        RegQueryValueExW,
    };

    /// UTF-16, NUL-terminated, for a Win32 wide-string argument.
@@ -374,9 +390,8 @@ mod win {
        let subkey = wide("Software\\Valve\\Steam");
        let mut hkey: HKEY = std::ptr::null_mut();
        // SAFETY: valid HKEY constant, NUL-terminated subkey, out-param for the handle.
-        let rc = unsafe {
-            RegOpenKeyExW(HKEY_CURRENT_USER, subkey.as_ptr(), 0, KEY_READ, &mut hkey)
-        };
+        let rc =
+            unsafe { RegOpenKeyExW(HKEY_CURRENT_USER, subkey.as_ptr(), 0, KEY_READ, &mut hkey) };
        (rc == ERROR_SUCCESS).then_some(hkey)
    }

@@ -463,13 +478,20 @@ mod tests {

    #[test]
    fn registry_string_lengths_are_bounded_and_trimmed() {
-        assert_eq!(validate_reg_len(5), None, "odd byte lengths are invalid UTF-16");
+        assert_eq!(
+            validate_reg_len(5),
+            None,
+            "odd byte lengths are invalid UTF-16"
+        );
        assert_eq!(validate_reg_len(MAX_STEAM_PATH_BYTES + 2), None);
        assert_eq!(validate_reg_len(8), Some(4));

        let raw = "C:\\Steam\0ignored".encode_utf16().collect::<Vec<_>>();
        let returned_bytes = ("C:\\Steam\0".encode_utf16().count() * 2) as u32;
-        assert_eq!(decode_reg_sz(raw, returned_bytes).as_deref(), Some("C:\\Steam"));
+        assert_eq!(
+            decode_reg_sz(raw, returned_bytes).as_deref(),
+            Some("C:\\Steam")
+        );
    }

    #[test]
@@ -495,10 +517,13 @@ mod tests {
            "contentstatsid" "12345"
        }"#;
        let got = parse_library_paths(current);
-        assert_eq!(got, vec![
-            PathBuf::from("/home/eric/.local/share/Steam"),
-            PathBuf::from("/mnt/games/SteamLibrary"),
-        ]);
+        assert_eq!(
+            got,
+            vec![
+                PathBuf::from("/home/eric/.local/share/Steam"),
+                PathBuf::from("/mnt/games/SteamLibrary"),
+            ]
+        );

        // Legacy shape: numeric keys map straight to path strings.
        let legacy = r#""LibraryFolders" {
@@ -522,13 +547,25 @@ mod tests {
        let environ = b"PATH=/usr/bin\0SteamAppId=440\0HOME=/home/x\0SteamGameId=440\0";
        assert_eq!(parse_steam_app_id_from_environ(environ), Some(440));
        // Nonzero requirement: SteamAppId=0 (the launcher itself) is ignored.
-        assert_eq!(parse_steam_app_id_from_environ(b"SteamAppId=0\0FOO=bar\0"), None);
+        assert_eq!(
+            parse_steam_app_id_from_environ(b"SteamAppId=0\0FOO=bar\0"),
+            None
+        );
        // Absent → None (a non-Steam process).
-        assert_eq!(parse_steam_app_id_from_environ(b"PATH=/usr/bin\0HOME=/home/x\0"), None);
+        assert_eq!(
+            parse_steam_app_id_from_environ(b"PATH=/usr/bin\0HOME=/home/x\0"),
+            None
+        );
        // Not fooled by a different var that merely contains the substring.
-        assert_eq!(parse_steam_app_id_from_environ(b"MY_SteamAppId=999\0"), None);
+        assert_eq!(
+            parse_steam_app_id_from_environ(b"MY_SteamAppId=999\0"),
+            None
+        );
        // Garbage value → None, no panic.
-        assert_eq!(parse_steam_app_id_from_environ(b"SteamAppId=notanumber\0"), None);
+        assert_eq!(
+            parse_steam_app_id_from_environ(b"SteamAppId=notanumber\0"),
+            None
+        );
    }

    #[test]
@@ -234,10 +234,20 @@ mod tests {
 }
 "#;
        let root = parse(acf).unwrap();
-        assert_eq!(root.get_path(&["AppState", "name"]).and_then(Value::as_str), Some("Counter-Strike 2"));
-        assert_eq!(root.get_path(&["AppState", "appid"]).and_then(Value::as_str), Some("730"));
+        assert_eq!(
+            root.get_path(&["AppState", "name"]).and_then(Value::as_str),
+            Some("Counter-Strike 2")
+        );
+        assert_eq!(
+            root.get_path(&["AppState", "appid"])
+                .and_then(Value::as_str),
+            Some("730")
+        );
        // Case-insensitive key lookup.
-        assert_eq!(root.get_path(&["appstate", "NAME"]).and_then(Value::as_str), Some("Counter-Strike 2"));
+        assert_eq!(
+            root.get_path(&["appstate", "NAME"]).and_then(Value::as_str),
+            Some("Counter-Strike 2")
+        );
    }

    #[test]
@@ -262,8 +272,14 @@ mod tests {
 "#;
        let root = parse(vdf).unwrap();
        let lf = root.get("libraryfolders").unwrap();
-        assert_eq!(lf.get_path(&["0", "path"]).and_then(Value::as_str), Some(r"C:\Program Files (x86)\Steam"));
-        assert_eq!(lf.get_path(&["1", "path"]).and_then(Value::as_str), Some("/home/eric/.local/share/Steam"));
+        assert_eq!(
+            lf.get_path(&["0", "path"]).and_then(Value::as_str),
+            Some(r"C:\Program Files (x86)\Steam")
+        );
+        assert_eq!(
+            lf.get_path(&["1", "path"]).and_then(Value::as_str),
+            Some("/home/eric/.local/share/Steam")
+        );
        // The library folder ids are iterable for discovery.
        let ids: Vec<&str> = lf.entries().iter().map(|(k, _)| k.as_str()).collect();
        assert_eq!(ids, vec!["0", "1"]);
@@ -292,7 +308,14 @@ mod tests {
 "#;
        let root = parse(reg).unwrap();
        let appid = root
-            .get_path(&["Registry", "HKCU", "Software", "Valve", "Steam", "RunningAppID"])
+            .get_path(&[
+                "Registry",
+                "HKCU",
+                "Software",
+                "Valve",
+                "Steam",
+                "RunningAppID",
+            ])
            .and_then(Value::as_str);
        assert_eq!(appid, Some("570"));
    }
@@ -301,7 +324,10 @@ mod tests {
    fn handles_comments_and_barewords() {
        let vdf = "// a comment\n\"root\"\n{\n\tbarekey barevalue // trailing\n}\n";
        let root = parse(vdf).unwrap();
-        assert_eq!(root.get_path(&["root", "barekey"]).and_then(Value::as_str), Some("barevalue"));
+        assert_eq!(
+            root.get_path(&["root", "barekey"]).and_then(Value::as_str),
+            Some("barevalue")
+        );
    }

    #[test]
@@ -89,9 +89,9 @@ impl HotkeyAction {

    pub fn tier(self) -> HotkeyTier {
        match self {
-            HotkeyAction::ToggleMute
-            | HotkeyAction::ToggleDeafen
-            | HotkeyAction::OpenSettings => HotkeyTier::AppWide,
+            HotkeyAction::ToggleMute | HotkeyAction::ToggleDeafen | HotkeyAction::OpenSettings => {
+                HotkeyTier::AppWide
+            }
            HotkeyAction::PushToTalk | HotkeyAction::LeaveRoom => HotkeyTier::RoomOnly,
        }
    }
@@ -278,7 +278,10 @@ mod tests {

    #[test]
    fn parse_single_character_case_folds() {
-        assert_eq!(parse_binding("M"), Some(KeyBinding::Character("m".to_string())));
+        assert_eq!(
+            parse_binding("M"),
+            Some(KeyBinding::Character("m".to_string()))
+        );
        assert_eq!(format_binding(parse_binding("m").as_ref()), "M");
    }
 }
@@ -41,7 +41,8 @@ pub fn identity_path() -> Option<PathBuf> {
 /// A *missing* file (first ever run, or right after a reset) is the normal
 /// create path.
 pub fn load_or_create() -> Result<SecretKey> {
-    let path = identity_path().context("could not determine a config directory for the identity key")?;
+    let path =
+        identity_path().context("could not determine a config directory for the identity key")?;
    load_or_create_at(&path)
 }

@@ -49,7 +50,8 @@ pub fn load_or_create() -> Result<SecretKey> {
 /// deliberate "Regenerate identity" / unlink action — the old id is discarded and
 /// unrecoverable, so callers should confirm with the user first.
 pub fn regenerate() -> Result<SecretKey> {
-    let path = identity_path().context("could not determine a config directory for the identity key")?;
+    let path =
+        identity_path().context("could not determine a config directory for the identity key")?;
    let key = SecretKey::generate();
    save_at(&path, &key)?;
    Ok(key)
@@ -57,7 +59,8 @@ pub fn regenerate() -> Result<SecretKey> {

 /// Atomic, `0600` write at the default identity path. See [`save_at`].
 pub fn save(key: &SecretKey) -> Result<()> {
-    let path = identity_path().context("could not determine a config directory for the identity key")?;
+    let path =
+        identity_path().context("could not determine a config directory for the identity key")?;
    save_at(&path, key)
 }

@@ -80,13 +83,15 @@ fn load_or_create_at(path: &std::path::Path) -> Result<SecretKey> {
 /// perms are applied before the rename so the secret is never briefly
 /// world-readable.
 fn save_at(path: &std::path::Path, key: &SecretKey) -> Result<()> {
-    let parent = path.parent().context("identity path has no parent directory")?;
+    let parent = path
+        .parent()
+        .context("identity path has no parent directory")?;
    fs::create_dir_all(parent).with_context(|| format!("failed to create {}", parent.display()))?;

    let tmp = parent.join(format!(".identity.key.tmp.{}", std::process::id()));
    {
-        let mut f =
-            fs::File::create(&tmp).with_context(|| format!("failed to create {}", tmp.display()))?;
+        let mut f = fs::File::create(&tmp)
+            .with_context(|| format!("failed to create {}", tmp.display()))?;
        #[cfg(unix)]
        {
            use std::os::unix::fs::PermissionsExt;
@@ -1,26 +1,28 @@
-pub mod audio;
-pub mod codec;
-pub mod dsp;
-pub mod network;
-pub mod protocol;
-pub mod core;
 pub mod app;
-pub mod config;
-pub mod identity;
-pub mod friends;
-pub mod presence;
-pub mod presence_net;
-pub mod theme;
-pub mod notify;
-pub mod screenshare;
-pub mod sanitize;
+pub mod audio;
 pub mod avatar;
 pub mod background;
-pub mod recents;
+pub mod codec;
+pub mod config;
+pub mod core;
 pub mod discovery;
-pub mod hotkeys;
+pub mod dsp;
 pub mod files;
+pub mod friends;
 pub mod game;
+pub mod hotkeys;
+pub mod identity;
+pub mod network;
+pub mod notify;
+pub mod playlist;
+pub mod presence;
+pub mod presence_net;
+pub mod protocol;
+pub mod recents;
+pub mod sanitize;
+pub mod screenshare;
+pub mod theme;
+pub mod widget;

 use std::fs::File;
 use std::path::{Path, PathBuf};
@@ -73,7 +75,8 @@ pub fn redact_for_log(value: &str) -> String {
 }

 pub fn short_bytes_hex(bytes: &[u8]) -> String {
-    bytes.iter()
+    bytes
+        .iter()
        .take(6)
        .map(|b| format!("{b:02x}"))
        .collect::<Vec<_>>()
@@ -81,7 +84,10 @@ pub fn short_bytes_hex(bytes: &[u8]) -> String {
 }

 fn rotated_log_path(path: &Path) -> PathBuf {
-    let file_name = path.file_name().and_then(|n| n.to_str()).unwrap_or("peerspeak.log");
+    let file_name = path
+        .file_name()
+        .and_then(|n| n.to_str())
+        .unwrap_or("peerspeak.log");
    path.with_file_name(format!("{file_name}.1"))
 }

@@ -98,7 +104,10 @@ fn prepare_log_file_with_limit(path: &Path, max_bytes: u64) -> std::io::Result<F
        let rotated = rotated_log_path(path);
        let _ = std::fs::remove_file(&rotated);
        if std::fs::rename(path, &rotated).is_err() {
-            let _ = std::fs::OpenOptions::new().write(true).truncate(true).open(path);
+            let _ = std::fs::OpenOptions::new()
+                .write(true)
+                .truncate(true)
+                .open(path);
        }
    }

@@ -1,16 +1,16 @@
-use crate::network::{NetworkTransport, NetError, ConnEvent};
-use iroh::{Endpoint, EndpointId};
-use iroh::endpoint::{Connection, ConnectionError, VarInt};
+use crate::network::{ConnEvent, NetError, NetworkTransport};
+use async_trait::async_trait;
 use bytes::Bytes;
+use iroh::endpoint::{Connection, ConnectionError, VarInt};
+use iroh::{Endpoint, EndpointId};
+use std::collections::{HashMap, HashSet};
+use std::sync::{Arc, Mutex as StdMutex};
+use std::time::Duration;
 use tokio::sync::mpsc;
 use tokio::sync::mpsc::Receiver;
-use std::sync::{Arc, Mutex as StdMutex};
-use std::collections::{HashMap, HashSet};
-use std::time::Duration;
-use async_trait::async_trait;

-use crate::protocol::{AUDIO_ALPN, FILES_ALPN};
 use crate::files::{AttachmentId, ChatAttachment};
+use crate::protocol::{AUDIO_ALPN, FILES_ALPN};

 /// Per-peer datagram send queue depth. Audio is real-time, so a backlog is
 /// useless latency — keep it shallow and drop the oldest frame when full.
@@ -111,7 +111,13 @@ impl Shared {
        let shared = self.clone();
        let supervisor = tokio::spawn(supervise(shared, peer_id, inbound_rx));
        let inbound_tx_ret = inbound_tx.clone();
-        peers.insert(peer_id, PeerHandle { supervisor, inbound_tx });
+        peers.insert(
+            peer_id,
+            PeerHandle {
+                supervisor,
+                inbound_tx,
+            },
+        );
        crate::log_msg(&format!("Transport: supervising peer {:?}", peer_id));
        inbound_tx_ret
    }
@@ -123,7 +129,10 @@ impl Shared {
        self.addrs.lock().unwrap().remove(&peer_id);
        if let Some(handle) = self.peers.lock().await.remove(&peer_id) {
            handle.supervisor.abort();
-            crate::log_msg(&format!("Transport: stopped supervising peer {:?}", peer_id));
+            crate::log_msg(&format!(
+                "Transport: stopped supervising peer {:?}",
+                peer_id
+            ));
        }
    }

@@ -208,12 +217,15 @@ async fn supervise(
    let mut backoff = INITIAL_BACKOFF;

    // Show "connecting" until the first link is actually up.
-    let _ = shared.conn_events_tx.try_send(ConnEvent::Connecting(peer_id));
+    let _ = shared
+        .conn_events_tx
+        .try_send(ConnEvent::Connecting(peer_id));

-    let mut conn = match obtain_conn(&shared, peer_id, is_dialer, &mut inbound_rx, &mut backoff).await {
-        Some(conn) => conn,
-        None => return, // retired before we ever connected
-    };
+    let mut conn =
+        match obtain_conn(&shared, peer_id, is_dialer, &mut inbound_rx, &mut backoff).await {
+            Some(conn) => conn,
+            None => return, // retired before we ever connected
+        };

    loop {
        // A healthy link resets the dialer's backoff for the next outage.
@@ -223,8 +235,14 @@ async fn supervise(
        shared.senders.lock().unwrap().insert(peer_id, send_tx);
        // Publish the live connection so an intentional leave can close it with
        // the goodbye code.
-        shared.live_conns.lock().unwrap().insert(peer_id, conn.clone());
-        let _ = shared.conn_events_tx.try_send(ConnEvent::Connected(peer_id));
+        shared
+            .live_conns
+            .lock()
+            .unwrap()
+            .insert(peer_id, conn.clone());
+        let _ = shared
+            .conn_events_tx
+            .try_send(ConnEvent::Connected(peer_id));
        crate::log_msg(&format!("Transport: peer {:?} link up", peer_id));

        // Run until the link dies, a replacement arrives, or we're retired. The
@@ -272,21 +290,36 @@ async fn supervise(
        match wake {
            Wake::Shutdown => return,
            Wake::Replacement(new_conn) => {
-                crate::log_msg(&format!("Transport: peer {:?} replaced with new inbound link", peer_id));
-                let _ = shared.conn_events_tx.try_send(ConnEvent::Connecting(peer_id));
+                crate::log_msg(&format!(
+                    "Transport: peer {:?} replaced with new inbound link",
+                    peer_id
+                ));
+                let _ = shared
+                    .conn_events_tx
+                    .try_send(ConnEvent::Connecting(peer_id));
                conn = new_conn;
            }
            Wake::Closed(reason) => {
                // A graceful application close means the peer left on purpose —
                // don't reconnect; tell the core to evict it now.
                if is_graceful_leave(&reason) {
-                    crate::log_msg(&format!("Transport: peer {:?} left gracefully ({:?})", peer_id, reason));
+                    crate::log_msg(&format!(
+                        "Transport: peer {:?} left gracefully ({:?})",
+                        peer_id, reason
+                    ));
                    let _ = shared.conn_events_tx.try_send(ConnEvent::Left(peer_id));
                    return;
                }
-                crate::log_msg(&format!("Transport: peer {:?} link dropped; reconnecting", peer_id));
-                let _ = shared.conn_events_tx.try_send(ConnEvent::Connecting(peer_id));
-                conn = match obtain_conn(&shared, peer_id, is_dialer, &mut inbound_rx, &mut backoff).await {
+                crate::log_msg(&format!(
+                    "Transport: peer {:?} link dropped; reconnecting",
+                    peer_id
+                ));
+                let _ = shared
+                    .conn_events_tx
+                    .try_send(ConnEvent::Connecting(peer_id));
+                conn = match obtain_conn(&shared, peer_id, is_dialer, &mut inbound_rx, &mut backoff)
+                    .await
+                {
                    Some(conn) => conn,
                    None => return, // retired while reconnecting
                };
@@ -405,7 +438,10 @@ impl iroh::protocol::ProtocolHandler for AudioRouter {
            // only happens if links are churning, and the supervisor gets the next one.
            let inbound_tx = shared.ensure_supervisor(peer_id).await;
            if inbound_tx.try_send(connection).is_err() {
-                crate::log_msg(&format!("Transport: dropped inbound link from {:?} (queue full)", peer_id));
+                crate::log_msg(&format!(
+                    "Transport: dropped inbound link from {:?} (queue full)",
+                    peer_id
+                ));
            }
            Ok(())
        }
@@ -545,7 +581,14 @@ impl IrohTransport {
    /// all supervisors so none linger redialing the about-to-close endpoint.
    /// Call this before shutting the router down.
    pub async fn leave(&self) {
-        let conns: Vec<Connection> = self.shared.live_conns.lock().unwrap().drain().map(|(_, c)| c).collect();
+        let conns: Vec<Connection> = self
+            .shared
+            .live_conns
+            .lock()
+            .unwrap()
+            .drain()
+            .map(|(_, c)| c)
+            .collect();
        for conn in &conns {
            conn.close(VarInt::from_u32(GOODBYE_CODE), b"leave");
        }
@@ -594,17 +637,21 @@ impl IrohTransport {
        self.shared.served_files.lock().unwrap().insert(id, bytes);
    }

-    /// Fetch a chat attachment's bytes from its sender over the file plane. Dials
-    /// the sender on `FILES_ALPN` (preferring a known full address), writes the
-    /// 32-byte id, and reads the response bounded by the descriptor's declared
-    /// size (which the caller has already validated against the global cap). The
-    /// read limit means a malicious sender can't stream us more than advertised.
-    pub async fn fetch_attachment(
+    /// Drop a previously-served blob (e.g. a music track no longer current-or-next).
+    pub fn forget_attachment(&self, id: AttachmentId) {
+        self.shared.served_files.lock().unwrap().remove(&id);
+    }
+
+    /// Fetch `size` bytes stored under `id` from peer `from` over the files plane.
+    /// Shared core of `fetch_attachment` and music-track fetching: dials
+    /// `FILES_ALPN`, writes the 32-byte id, and reads bounded by `size`.
+    pub async fn fetch_blob(
        &self,
        from: EndpointId,
-        att: &ChatAttachment,
+        id: AttachmentId,
+        size: u64,
    ) -> Result<Vec<u8>, NetError> {
-        if !crate::files::size_within_cap(att.size) {
+        if !crate::files::size_within_cap(size) {
            return Err(NetError::Other("attachment size out of range".to_string()));
        }
        let addr = self.shared.addrs.lock().unwrap().get(&from).cloned();
@@ -623,22 +670,84 @@ impl IrohTransport {
            .open_bi()
            .await
            .map_err(|e| NetError::Other(format!("file fetch: open stream failed: {e}")))?;
-        send.write_all(&att.id)
+        send.write_all(&id)
            .await
            .map_err(|e| NetError::Other(format!("file fetch: request write failed: {e}")))?;
        send.finish()
            .map_err(|e| NetError::Other(format!("file fetch: request finish failed: {e}")))?;

-        let read = recv.read_to_end(att.size as usize);
+        let read = recv.read_to_end(size as usize);
        let bytes = tokio::time::timeout(FILE_FETCH_TIMEOUT, read)
            .await
            .map_err(|_| NetError::Other("file fetch: read timed out".to_string()))?
            .map_err(|e| NetError::Other(format!("file fetch: read failed: {e}")))?;
        if bytes.is_empty() {
-            return Err(NetError::Other("file fetch: sender no longer has the file".to_string()));
+            return Err(NetError::Other(
+                "file fetch: sender no longer has the file".to_string(),
+            ));
        }
        Ok(bytes)
    }
+
+    /// Snapshot the selected QUIC path of every live audio connection, for the
+    /// UI's per-peer connection badge (direct/relay, RTT, loss, bitrate).
+    /// Cheap and lock-light: the `live_conns` guard is released before touching
+    /// any connection, and `Connection::paths()` reads shared state without I/O.
+    pub fn connection_stats(&self) -> Vec<(EndpointId, crate::network::PathSnapshot)> {
+        // Clone the connections out so the map lock isn't held while we inspect
+        // paths (a supervisor inserts/removes entries as links come and go).
+        let conns: Vec<(EndpointId, Connection)> = self
+            .shared
+            .live_conns
+            .lock()
+            .unwrap()
+            .iter()
+            .map(|(id, conn)| (*id, conn.clone()))
+            .collect();
+        conns
+            .into_iter()
+            .filter_map(|(id, conn)| {
+                let paths = conn.paths();
+                // The selected path is the one carrying application data. In the
+                // brief window where none is flagged (e.g. mid-migration), fall
+                // back to the first open path rather than dropping the badge.
+                let path = paths
+                    .iter()
+                    .find(|p| p.is_selected())
+                    .or_else(|| paths.iter().next())?;
+                let stats = path.stats();
+                // Per-variant display: `TransportAddr`'s own `Display` prefixes
+                // a scheme ("ip:1.2.3.4:5") that's noise next to the badge's
+                // Direct/Relay label.
+                let remote_addr = match path.remote_addr() {
+                    iroh::TransportAddr::Ip(sock) => sock.to_string(),
+                    iroh::TransportAddr::Relay(url) => url.to_string(),
+                    other => other.to_string(),
+                };
+                Some((
+                    id,
+                    crate::network::PathSnapshot {
+                        is_relay: path.remote_addr().is_relay(),
+                        remote_addr,
+                        rtt: stats.rtt,
+                        tx_bytes: stats.udp_tx.bytes,
+                        rx_bytes: stats.udp_rx.bytes,
+                        tx_datagrams: stats.udp_tx.datagrams,
+                        lost_packets: stats.lost_packets,
+                    },
+                ))
+            })
+            .collect()
+    }
+
+    /// Fetch a chat attachment's bytes from its sender over the file plane.
+    pub async fn fetch_attachment(
+        &self,
+        from: EndpointId,
+        att: &ChatAttachment,
+    ) -> Result<Vec<u8>, NetError> {
+        self.fetch_blob(from, att.id, att.size).await
+    }
 }

 #[async_trait]
@@ -1,10 +1,10 @@
-use iroh::{EndpointId, EndpointAddr};
+use async_trait::async_trait;
 use bytes::Bytes;
+use iroh::{EndpointAddr, EndpointId};
+use serde::{Deserialize, Serialize};
+use std::str::FromStr;
 use thiserror::Error;
 use tokio::sync::mpsc::Receiver;
-use async_trait::async_trait;
-use serde::{Serialize, Deserialize};
-use std::str::FromStr;

 #[derive(Error, Debug)]
 pub enum NetError {
@@ -22,6 +22,38 @@ pub enum NetError {
    Other(String),
 }

+/// A peer's currently-broadcast music track + playback timeline (W22). Rides
+/// gossip presence so listeners can tune in, follow track changes, and keep in
+/// sync. Untrusted like `name`/`game`: the `name` is sanitized and `size` is
+/// cap-checked at gossip ingest. Bytes never ride gossip — they are fetched
+/// point-to-point over the files plane by `id`, exactly like a chat attachment.
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
+pub struct MusicPresence {
+    /// Files-plane handle to fetch this track's bytes (minted per track by the DJ).
+    pub id: crate::files::AttachmentId,
+    /// Sanitized display name (track filename). Untrusted; cleaned at ingest.
+    pub name: String,
+    /// Byte length, bounds the listener's fetch. Must be `<= MAX_ATTACHMENT_BYTES`.
+    pub size: u64,
+    /// True while the DJ has the track paused.
+    pub paused: bool,
+    /// Wall-clock ms (UNIX epoch) of the timeline anchor. While playing, the true
+    /// playhead is `position_ms + (now_ms - anchor_ms)`; while paused it is
+    /// frozen at `position_ms`. Re-stamped on every play/pause/seek.
+    pub anchor_ms: u64,
+    /// Playhead position (ms) at `anchor_ms`.
+    pub position_ms: u64,
+    /// Files-plane handle for the DJ's NEXT track, so listeners can prefetch it
+    /// for a gapless skip. `None` when there is no distinct next track (single
+    /// item playlist) or the DJ isn't ready. Equals a future `id` once that
+    /// track plays.
+    #[serde(default)]
+    pub next_id: Option<crate::files::AttachmentId>,
+    /// Byte length of the next track; bounds the prefetch. Cap-checked at ingest.
+    #[serde(default)]
+    pub next_size: Option<u64>,
+}
+
 #[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
 pub struct PeerState {
    pub name: String,
@@ -48,6 +80,10 @@ pub struct PeerState {
    /// Defaulted so peers/configs predating the field still deserialize.
    #[serde(default)]
    pub game: Option<String>,
+    /// This peer's currently-broadcast music track and playback timeline, or
+    /// `None` when not broadcasting. Defaulted so pre-W22 peers deserialize.
+    #[serde(default)]
+    pub music: Option<MusicPresence>,
 }

 /// The locally-owned, "sticky" pieces of our own presence: the identity fields
@@ -70,6 +106,8 @@ pub struct SelfPresence {
    /// (see `crate::sanitize::sanitize_game_label`) before being stored here, so
    /// the outgoing announce carries a safe value.
    pub game: Option<String>,
+    /// Our current broadcast timeline, or `None` when not broadcasting / not playing.
+    pub music: Option<MusicPresence>,
 }

 impl SelfPresence {
@@ -89,6 +127,7 @@ impl SelfPresence {
            sharing,
            avatar: self.avatar.clone(),
            game: self.game.clone(),
+            music: self.music.clone(),
        }
    }
 }
@@ -106,6 +145,13 @@ pub enum RoomEvent {
    /// from `PeerLeft` precisely so a momentary `NeighborDown` can't tear down the
    /// reconnect path the way it used to.
    PeerConnectionLost(EndpointId),
+    /// A validly signed gossip payload was rejected only because its timestamp is
+    /// outside the replay-protection window. The peer is not in the roster yet,
+    /// so this surfaces as a room-level warning instead of a peer-card state.
+    ClockSkewSuspected {
+        author: EndpointId,
+        skew_ms: i64,
+    },
    /// A peer sent a room text-chat message. Carries the sender's id, their
    /// display name (embedded so it shows even without a presence entry), the
    /// text, and a sender-stamped millisecond timestamp.
@@ -138,6 +184,32 @@ pub enum ConnEvent {
    Left(EndpointId),
 }

+/// Owned snapshot of a peer's *selected* QUIC path (the one currently carrying
+/// application data), taken from the live audio connection for the UI's
+/// connection-transparency badge. Counters are cumulative for the path's
+/// lifetime; rate/loss derivation over a poll window happens in
+/// `core::connstats` (which also detects path switches via `remote_addr`).
+#[derive(Debug, Clone, PartialEq)]
+pub struct PathSnapshot {
+    /// True when the path runs through a relay server, false for a direct
+    /// (holepunched or local) IP path.
+    pub is_relay: bool,
+    /// The path's remote transport address: `ip:port` for a direct path, the
+    /// relay URL for a relayed one.
+    pub remote_addr: String,
+    /// Current QUIC round-trip-time estimate for the path.
+    pub rtt: std::time::Duration,
+    /// Cumulative bytes sent in UDP datagrams on the path.
+    pub tx_bytes: u64,
+    /// Cumulative bytes received in UDP datagrams on the path.
+    pub rx_bytes: u64,
+    /// Cumulative UDP datagrams sent on the path (the loss denominator: for our
+    /// small voice frames these map ~1:1 to QUIC packets).
+    pub tx_datagrams: u64,
+    /// Cumulative packets detected lost on the path.
+    pub lost_packets: u64,
+}
+
 #[derive(Serialize, Deserialize, Clone, Debug)]
 pub struct PeerSpeakTicket {
    pub host_addr: iroh::EndpointAddr,
@@ -160,10 +232,12 @@ impl PeerSpeakTicket {
    /// is idempotent.
    pub fn restamp(ticket_str: &str, my_addr: iroh::EndpointAddr) -> String {
        match ticket_str.parse::<PeerSpeakTicket>() {
-            Ok(t) => {
-                PeerSpeakTicket { host_addr: my_addr, topic_id: t.topic_id, name: t.name }
-                    .to_string()
+            Ok(t) => PeerSpeakTicket {
+                host_addr: my_addr,
+                topic_id: t.topic_id,
+                name: t.name,
            }
+            .to_string(),
            Err(_) => ticket_str.to_string(),
        }
    }
@@ -172,7 +246,10 @@ impl PeerSpeakTicket {
    /// can't be parsed or carries no label. Pure; used to label the gathering both
    /// in the room UI and in the presence we report to friends.
    pub fn label_of(ticket_str: &str) -> String {
-        ticket_str.parse::<PeerSpeakTicket>().map(|t| t.name).unwrap_or_default()
+        ticket_str
+            .parse::<PeerSpeakTicket>()
+            .map(|t| t.name)
+            .unwrap_or_default()
    }

    /// The room's `topic_id` embedded in a ticket string, or `None` if the ticket
@@ -180,7 +257,10 @@ impl PeerSpeakTicket {
    /// the recents list (the host address and label change between members/sessions,
    /// but the topic uniquely identifies the gathering).
    pub fn topic_of(ticket_str: &str) -> Option<[u8; 32]> {
-        ticket_str.parse::<PeerSpeakTicket>().ok().map(|t| t.topic_id)
+        ticket_str
+            .parse::<PeerSpeakTicket>()
+            .ok()
+            .map(|t| t.topic_id)
    }
 }

@@ -203,8 +283,8 @@ impl FromStr for PeerSpeakTicket {
    fn from_str(s: &str) -> Result<Self, Self::Err> {
        let decoded = base64::Engine::decode(&base64::engine::general_purpose::URL_SAFE_NO_PAD, s)
            .map_err(|e| NetError::InvalidTicket(e.to_string()))?;
-        let ticket: PeerSpeakTicket = serde_json::from_slice(&decoded)
-            .map_err(|e| NetError::InvalidTicket(e.to_string()))?;
+        let ticket: PeerSpeakTicket =
+            serde_json::from_slice(&decoded).map_err(|e| NetError::InvalidTicket(e.to_string()))?;
        Ok(ticket)
    }
 }
@@ -284,13 +364,13 @@ pub trait RoomState: Send + Sync {
    async fn subscribe_events(&self) -> Result<Receiver<RoomEvent>, NetError>;
 }

-pub mod iroh_impl;
 pub mod gossip;
+pub mod iroh_impl;

 #[cfg(test)]
 mod tests {
    use super::*;
-    use iroh::{SecretKey, EndpointAddr};
+    use iroh::{EndpointAddr, SecretKey};

    fn sample_peer_state() -> PeerState {
        let secret = SecretKey::generate();
@@ -303,6 +383,7 @@ mod tests {
            sharing: None,
            avatar: crate::avatar::Avatar::default(),
            game: None,
+            music: None,
        }
    }

@@ -327,9 +408,12 @@ mod tests {
        let host = SecretKey::generate().public();
        let topic_id = [3u8; 32];
        // A labelled ticket: restamp keeps the label, label_of reads it.
-        let labelled =
-            PeerSpeakTicket { host_addr: EndpointAddr::from(host), topic_id, name: "HangOut".into() }
-                .to_string();
+        let labelled = PeerSpeakTicket {
+            host_addr: EndpointAddr::from(host),
+            topic_id,
+            name: "HangOut".into(),
+        }
+        .to_string();
        assert_eq!(PeerSpeakTicket::label_of(&labelled), "HangOut");
        let member = SecretKey::generate().public();
        let restamped = PeerSpeakTicket::restamp(&labelled, EndpointAddr::from(member));
@@ -366,10 +450,8 @@ mod tests {

        // valid URL-safe-base64 that decodes to non-JSON bytes
        let bad_json = b"hello world";
-        let encoded = base64::Engine::encode(
-            &base64::engine::general_purpose::URL_SAFE_NO_PAD,
-            bad_json,
-        );
+        let encoded =
+            base64::Engine::encode(&base64::engine::general_purpose::URL_SAFE_NO_PAD, bad_json);
        let res3 = encoded.parse::<PeerSpeakTicket>();
        assert!(matches!(res3, Err(NetError::InvalidTicket(_))));
    }
@@ -380,9 +462,12 @@ mod tests {
        let host = SecretKey::generate().public();
        let member = SecretKey::generate().public();
        let topic_id = [42u8; 32];
-        let original =
-            PeerSpeakTicket { host_addr: EndpointAddr::from(host), topic_id, name: "HangOut".into() }
-                .to_string();
+        let original = PeerSpeakTicket {
+            host_addr: EndpointAddr::from(host),
+            topic_id,
+            name: "HangOut".into(),
+        }
+        .to_string();

        let restamped_str = PeerSpeakTicket::restamp(&original, EndpointAddr::from(member));
        let restamped = restamped_str.parse::<PeerSpeakTicket>().unwrap();
@@ -397,18 +482,27 @@ mod tests {
    fn test_restamp_is_idempotent_for_same_addr() {
        let me = SecretKey::generate().public();
        let topic_id = [7u8; 32];
-        let mine =
-            PeerSpeakTicket { host_addr: EndpointAddr::from(me), topic_id, name: String::new() }
-                .to_string();
+        let mine = PeerSpeakTicket {
+            host_addr: EndpointAddr::from(me),
+            topic_id,
+            name: String::new(),
+        }
+        .to_string();
        // Re-stamping my own ticket with my own addr changes nothing.
-        assert_eq!(PeerSpeakTicket::restamp(&mine, EndpointAddr::from(me)), mine);
+        assert_eq!(
+            PeerSpeakTicket::restamp(&mine, EndpointAddr::from(me)),
+            mine
+        );
    }

    #[test]
    fn test_restamp_passes_through_unparseable() {
        let me = SecretKey::generate().public();
        // A malformed ticket is returned unchanged (the join will fail anyway).
-        assert_eq!(PeerSpeakTicket::restamp("not-a-ticket", EndpointAddr::from(me)), "not-a-ticket");
+        assert_eq!(
+            PeerSpeakTicket::restamp("not-a-ticket", EndpointAddr::from(me)),
+            "not-a-ticket"
+        );
    }

    #[test]
@@ -418,6 +512,7 @@ mod tests {
            name: "Alice".to_string(),
            avatar: crate::avatar::Avatar::default(),
            game: Some("Half-Life 2".to_string()),
+            music: None,
        };
        // Volatile fields come from the call; sticky fields from the struct.
        let muted = presence.to_state(true, addr.clone(), Some("ticket".to_string()));
@@ -441,4 +536,21 @@ mod tests {
        let deserialized: PeerState = serde_json::from_str(&serialized).unwrap();
        assert_eq!(original, deserialized);
    }
+
+    #[test]
+    fn music_presence_serde_round_trip() {
+        let original = MusicPresence {
+            id: [3u8; 32],
+            name: "track.ogg".to_string(),
+            size: 1234,
+            paused: false,
+            anchor_ms: 1_700_000_000_000,
+            position_ms: 42_000,
+            next_id: None,
+            next_size: None,
+        };
+        let serialized = serde_json::to_string(&original).unwrap();
+        let deserialized: MusicPresence = serde_json::from_str(&serialized).unwrap();
+        assert_eq!(original, deserialized);
+    }
 }
@@ -11,12 +11,16 @@
 //! missing chime should never disrupt a call.

 use std::collections::HashMap;
+use std::fs::OpenOptions;
+use std::io::Write;
 use std::path::{Path, PathBuf};
 use std::process::{Command, Stdio};
-use std::sync::atomic::{AtomicBool, Ordering};
+use std::sync::atomic::{AtomicBool, AtomicU64, Ordering};
 use std::sync::{Mutex, OnceLock};
+use std::time::{SystemTime, UNIX_EPOCH};

 static ENABLED: AtomicBool = AtomicBool::new(true);
+static TEMP_WAV_COUNTER: AtomicU64 = AtomicU64::new(0);

 /// Per-sound enable flags (W6), indexed by `Sound::index`. The master `ENABLED`
 /// toggle gates everything; these silence individual events while the master
@@ -57,7 +61,6 @@ pub fn should_play(master_enabled: bool, sound_enabled: bool) -> bool {
    master_enabled && sound_enabled
 }

-
 /// A notification event with a distinct chime.
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub enum Sound {
@@ -195,14 +198,38 @@ fn cached_path(sound: Sound) -> Option<PathBuf> {
    if let Some(path) = guard.get(sound.name()) {
        return Some(path.clone());
    }
-    let path = std::env::temp_dir().join(format!("peerspeak-{}.wav", sound.name()));
-    if std::fs::write(&path, sound.bytes()).is_err() {
-        return None;
-    }
+    let path = match write_private_wav(&std::env::temp_dir(), sound.name(), sound.bytes()) {
+        Ok(path) => path,
+        Err(_) => return None,
+    };
    guard.insert(sound.name(), path.clone());
    Some(path)
 }

+fn write_private_wav(dir: &Path, stem: &str, bytes: &[u8]) -> std::io::Result<PathBuf> {
+    let counter = TEMP_WAV_COUNTER.fetch_add(1, Ordering::Relaxed);
+    let nanos = SystemTime::now()
+        .duration_since(UNIX_EPOCH)
+        .unwrap_or_default()
+        .as_nanos();
+    let path = dir.join(format!(
+        "peerspeak-{stem}-{}-{counter}-{nanos}.wav",
+        std::process::id()
+    ));
+
+    let mut options = OpenOptions::new();
+    options.write(true).create_new(true);
+    #[cfg(unix)]
+    {
+        use std::os::unix::fs::OpenOptionsExt;
+        options.mode(0o600);
+    }
+
+    let mut file = options.open(&path)?;
+    file.write_all(bytes)?;
+    Ok(path)
+}
+
 #[cfg(any(windows, test))]
 fn escape_powershell_single_quoted(s: &str) -> String {
    s.replace('\'', "''")
@@ -249,6 +276,19 @@ fn spawn_player(path: &Path) {
 mod tests {
    use super::*;

+    static TEST_TEMP_COUNTER: AtomicU64 = AtomicU64::new(0);
+
+    fn temp_wav_dir(tag: &str) -> PathBuf {
+        let counter = TEST_TEMP_COUNTER.fetch_add(1, Ordering::Relaxed);
+        let dir = std::env::temp_dir().join(format!(
+            "peerspeak-notifytest-{}-{tag}-{counter}",
+            std::process::id()
+        ));
+        let _ = std::fs::remove_dir_all(&dir);
+        std::fs::create_dir_all(&dir).unwrap();
+        dir
+    }
+
    #[test]
    fn test_should_play_truth_table() {
        // Plays only when BOTH the master and the per-sound flag are on.
@@ -264,10 +304,7 @@ mod tests {
            escape_powershell_single_quoted(r"C:\Users\O'Brien\chime.wav"),
            r"C:\Users\O''Brien\chime.wav"
        );
-        assert_eq!(
-            escape_powershell_single_quoted("a'b'c"),
-            "a''b''c"
-        );
+        assert_eq!(escape_powershell_single_quoted("a'b'c"), "a''b''c");
    }

    #[test]
@@ -297,7 +334,10 @@ mod tests {
            // bare `~` -> home dir
            assert_eq!(expand_tilde("~"), home);
            // `~/sub/dir/file.wav` -> home joined with `sub/dir/file.wav`
-            assert_eq!(expand_tilde("~/sub/dir/file.wav"), home.join("sub/dir/file.wav"));
+            assert_eq!(
+                expand_tilde("~/sub/dir/file.wav"),
+                home.join("sub/dir/file.wav")
+            );
        }
        // absolute path (`/etc/foo.wav`) -> unchanged
        assert_eq!(expand_tilde("/etc/foo.wav"), PathBuf::from("/etc/foo.wav"));
@@ -310,10 +350,19 @@ mod tests {
        // leading/trailing whitespace is trimmed
        if let Some(home) = dirs::home_dir() {
            assert_eq!(expand_tilde("  ~  "), home);
-            assert_eq!(expand_tilde("  ~/sub/dir/file.wav  "), home.join("sub/dir/file.wav"));
+            assert_eq!(
+                expand_tilde("  ~/sub/dir/file.wav  "),
+                home.join("sub/dir/file.wav")
+            );
        }
-        assert_eq!(expand_tilde("  /etc/foo.wav  "), PathBuf::from("/etc/foo.wav"));
-        assert_eq!(expand_tilde("  foo/bar.wav  "), PathBuf::from("foo/bar.wav"));
+        assert_eq!(
+            expand_tilde("  /etc/foo.wav  "),
+            PathBuf::from("/etc/foo.wav")
+        );
+        assert_eq!(
+            expand_tilde("  foo/bar.wav  "),
+            PathBuf::from("foo/bar.wav")
+        );
    }

    #[test]
@@ -332,4 +381,61 @@ mod tests {
        // a `~`-prefixed path that resolves to a non-existent file -> Some(false)
        assert_eq!(validate_custom_path("~/non/existent/file.wav"), Some(false));
    }
+
+    #[test]
+    fn write_private_wav_writes_exact_bytes() {
+        let dir = temp_wav_dir("writes");
+        let bytes = b"RIFFpeerspeak-test";
+
+        let path = write_private_wav(&dir, "unit", bytes).unwrap();
+
+        assert!(path.exists());
+        assert_eq!(std::fs::read(&path).unwrap(), bytes);
+        let _ = std::fs::remove_dir_all(&dir);
+    }
+
+    #[cfg(unix)]
+    #[test]
+    fn write_private_wav_creates_0600_file() {
+        use std::os::unix::fs::PermissionsExt;
+
+        let dir = temp_wav_dir("mode");
+        let path = write_private_wav(&dir, "unit", b"mode").unwrap();
+
+        let mode = std::fs::metadata(&path).unwrap().permissions().mode() & 0o777;
+        assert_eq!(mode, 0o600);
+        let _ = std::fs::remove_dir_all(&dir);
+    }
+
+    #[test]
+    fn write_private_wav_uses_unique_paths() {
+        let dir = temp_wav_dir("unique");
+
+        let first = write_private_wav(&dir, "same-stem", b"first").unwrap();
+        let second = write_private_wav(&dir, "same-stem", b"second").unwrap();
+
+        assert_ne!(first, second);
+        assert!(first.exists());
+        assert!(second.exists());
+        assert_eq!(std::fs::read(&first).unwrap(), b"first");
+        assert_eq!(std::fs::read(&second).unwrap(), b"second");
+        let _ = std::fs::remove_dir_all(&dir);
+    }
+
+    #[test]
+    fn create_new_refuses_existing_path() {
+        let dir = temp_wav_dir("create-new");
+        let path = dir.join("preexisting.wav");
+        std::fs::write(&path, b"original").unwrap();
+
+        let err = std::fs::OpenOptions::new()
+            .write(true)
+            .create_new(true)
+            .open(&path)
+            .unwrap_err();
+
+        assert_eq!(err.kind(), std::io::ErrorKind::AlreadyExists);
+        assert_eq!(std::fs::read(&path).unwrap(), b"original");
+        let _ = std::fs::remove_dir_all(&dir);
+    }
 }
@@ -0,0 +1,115 @@
+use std::path::{Path, PathBuf};
+
+#[derive(Clone, Copy, PartialEq, Eq, Debug)]
+pub enum PlaylistKind {
+    M3u,
+    Pls,
+}
+
+/// Classify a path by extension into a playlist kind, or None if it is not a
+/// recognized playlist file. Case-insensitive: m3u/m3u8 -> M3u, pls -> Pls.
+pub fn playlist_kind(path: &Path) -> Option<PlaylistKind> {
+    let ext = path.extension()?.to_string_lossy();
+    match ext.to_ascii_lowercase().as_str() {
+        "m3u" | "m3u8" => Some(PlaylistKind::M3u),
+        "pls" => Some(PlaylistKind::Pls),
+        _ => None,
+    }
+}
+
+/// Parse an m3u/m3u8 or pls playlist into local audio file paths. Remote entries
+/// (http/https/ftp URLs) and non-audio entries are skipped; relative paths are
+/// resolved against `base_dir` (the playlist file's parent directory). Order is
+/// preserved. Does not touch the filesystem.
+pub fn parse_playlist(contents: &str, base_dir: &Path, kind: PlaylistKind) -> Vec<PathBuf> {
+    let entries: Vec<&str> = match kind {
+        PlaylistKind::M3u => contents
+            .lines()
+            .map(str::trim)
+            .filter(|line| !line.is_empty() && !line.starts_with('#'))
+            .collect(),
+        PlaylistKind::Pls => contents
+            .lines()
+            .filter_map(|line| {
+                let (key, value) = line.split_once('=')?;
+                key.trim()
+                    .to_ascii_lowercase()
+                    .starts_with("file")
+                    .then_some(value.trim())
+            })
+            .filter(|line| !line.is_empty())
+            .collect(),
+    };
+
+    entries
+        .into_iter()
+        .filter_map(|entry| playlist_entry_path(entry, base_dir))
+        .collect()
+}
+
+fn playlist_entry_path(entry: &str, base_dir: &Path) -> Option<PathBuf> {
+    let lower = entry.to_ascii_lowercase();
+    if lower.starts_with("http://") || lower.starts_with("https://") || lower.starts_with("ftp://")
+    {
+        return None;
+    }
+
+    let path = Path::new(entry);
+    let resolved = if path.is_absolute() {
+        path.to_path_buf()
+    } else {
+        base_dir.join(path)
+    };
+    let file_name = resolved.file_name()?.to_string_lossy();
+    crate::files::looks_like_audio_name(&file_name).then_some(resolved)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn m3u_skips_comments_and_remote_urls() {
+        let base = Path::new("/music/lists");
+        let contents = "\
+#EXTM3U
+#EXTINF:123,Artist - Song
+tracks/song.ogg
+https://example.com/stream.mp3
+";
+        assert_eq!(
+            parse_playlist(contents, base, PlaylistKind::M3u),
+            vec![PathBuf::from("/music/lists/tracks/song.ogg")]
+        );
+    }
+
+    #[test]
+    fn pls_keeps_file_values_and_skips_non_audio() {
+        let base = Path::new("/music");
+        let contents = "\
+[playlist]
+File1=one.flac
+Title1=One
+File2=notes.txt
+File3=/var/audio/two.MP3
+";
+        assert_eq!(
+            parse_playlist(contents, base, PlaylistKind::Pls),
+            vec![
+                PathBuf::from("/music/one.flac"),
+                PathBuf::from("/var/audio/two.MP3"),
+            ]
+        );
+    }
+
+    #[test]
+    fn playlist_kind_is_case_insensitive() {
+        assert_eq!(playlist_kind(Path::new("mix.M3U")), Some(PlaylistKind::M3u));
+        assert_eq!(
+            playlist_kind(Path::new("mix.m3u8")),
+            Some(PlaylistKind::M3u)
+        );
+        assert_eq!(playlist_kind(Path::new("mix.PLS")), Some(PlaylistKind::Pls));
+        assert_eq!(playlist_kind(Path::new("mix.txt")), None);
+    }
+}
@@ -36,8 +36,11 @@ pub enum PresenceMode {

 impl PresenceMode {
    /// All postures, default first — the option list for the Settings/home picker.
-    pub const ALL: [PresenceMode; 3] =
-        [PresenceMode::Normal, PresenceMode::Invisible, PresenceMode::Discoverable];
+    pub const ALL: [PresenceMode; 3] = [
+        PresenceMode::Normal,
+        PresenceMode::Invisible,
+        PresenceMode::Discoverable,
+    ];

    /// Whether this posture publishes to discovery (the only mode that does).
    pub fn publishes_to_discovery(self) -> bool {
@@ -100,7 +103,11 @@ pub fn should_answer(from: &EndpointId, friends: &FriendStore, mode: PresenceMod
    mode.answers_pings() && friends.contains(from)
 }

-/// What we learned about a friend from a successful ping reply.
+/// What we learned about a friend's reachability. `Online`/`InRoom` come from a
+/// successful ping reply (see [`interpret_pong`]); `Offline` is produced by the
+/// presence scheduler when a probe fails or the friend has no known address, so a
+/// friend who drops or leaves is *actively* downgraded rather than left showing a
+/// stale status. The UI also treats a missing entry as offline.
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub enum FriendPresence {
    /// Online, but not in a gathering we can join.
@@ -108,6 +115,8 @@ pub enum FriendPresence {
    /// Online and in a joinable gathering (name already sanitized, ticket already
    /// validated as parseable).
    InRoom { name: String, ticket: String },
+    /// Unreachable: the probe failed, or we have no address to probe yet.
+    Offline,
 }

 /// Interpret a peer's reply defensively. `from` must be the connection's
@@ -140,6 +149,20 @@ pub fn interpret_pong(msg: &ControlMsg, from: EndpointId) -> Option<FriendPresen
    }
 }

+/// Map a single probe outcome to a definitive [`FriendPresence`], used by the
+/// presence scheduler. `Some((reply, from))` is a received message from the
+/// authenticated remote `from`; `None` means the probe failed (offline /
+/// unreachable / refused). Anything that doesn't interpret as a real presence —
+/// a probe error, or a non-`Pong` reply — becomes [`FriendPresence::Offline`], so
+/// a friend who drops is actively downgraded instead of keeping a stale status.
+/// Pure so the scheduler's downgrade behaviour is unit-testable without a network.
+pub fn presence_from_probe(reply: Option<(&ControlMsg, EndpointId)>) -> FriendPresence {
+    match reply {
+        Some((msg, from)) => interpret_pong(msg, from).unwrap_or(FriendPresence::Offline),
+        None => FriendPresence::Offline,
+    }
+}
+
 #[cfg(test)]
 mod tests {
    use super::*;
@@ -173,7 +196,11 @@ mod tests {
        assert!(!should_answer(&friend, &friends, PresenceMode::Invisible));
        // Stranger is NEVER answered, in any mode.
        assert!(!should_answer(&stranger, &friends, PresenceMode::Normal));
-        assert!(!should_answer(&stranger, &friends, PresenceMode::Discoverable));
+        assert!(!should_answer(
+            &stranger,
+            &friends,
+            PresenceMode::Discoverable
+        ));
        assert!(!should_answer(&stranger, &friends, PresenceMode::Invisible));
    }

@@ -194,7 +221,10 @@ mod tests {
            ControlMsg::Ping,
            ControlMsg::Pong { room: None },
            ControlMsg::Pong {
-                room: Some(RoomPresence { name: "HangOut".into(), ticket: "abc".into() }),
+                room: Some(RoomPresence {
+                    name: "HangOut".into(),
+                    ticket: "abc".into(),
+                }),
            },
        ];
        for msg in cases {
@@ -225,19 +255,37 @@ mod tests {
        );
        // Valid ticket -> InRoom with a sanitized name.
        let t = valid_ticket(friend);
-        let got = interpret_pong(&ControlMsg::Pong {
-            room: Some(RoomPresence { name: "HangOut".into(), ticket: t.clone() }),
-        }, friend);
-        assert_eq!(got, Some(FriendPresence::InRoom { name: "HangOut".into(), ticket: t }));
+        let got = interpret_pong(
+            &ControlMsg::Pong {
+                room: Some(RoomPresence {
+                    name: "HangOut".into(),
+                    ticket: t.clone(),
+                }),
+            },
+            friend,
+        );
+        assert_eq!(
+            got,
+            Some(FriendPresence::InRoom {
+                name: "HangOut".into(),
+                ticket: t
+            })
+        );
    }

    #[test]
    fn interpret_pong_downgrades_a_garbage_ticket_to_online() {
        // A friend reporting a room with an unparseable ticket is treated as just
        // Online — no dead/hostile Join button is surfaced.
-        let got = interpret_pong(&ControlMsg::Pong {
-            room: Some(RoomPresence { name: "Trap".into(), ticket: "not-a-ticket".into() }),
-        }, id());
+        let got = interpret_pong(
+            &ControlMsg::Pong {
+                room: Some(RoomPresence {
+                    name: "Trap".into(),
+                    ticket: "not-a-ticket".into(),
+                }),
+            },
+            id(),
+        );
        assert_eq!(got, Some(FriendPresence::Online));
    }

@@ -246,20 +294,67 @@ mod tests {
        let friend = id();
        let attacker = id();
        let t = valid_ticket(attacker);
-        let got = interpret_pong(&ControlMsg::Pong {
-            room: Some(RoomPresence { name: "Redirect".into(), ticket: t }),
-        }, friend);
+        let got = interpret_pong(
+            &ControlMsg::Pong {
+                room: Some(RoomPresence {
+                    name: "Redirect".into(),
+                    ticket: t,
+                }),
+            },
+            friend,
+        );
        assert_eq!(got, Some(FriendPresence::Online));
    }

+    #[test]
+    fn presence_from_probe_maps_outcomes_to_definitive_status() {
+        let friend = id();
+        // A failed probe (no reply) is an explicit downgrade to Offline, so the UI
+        // clears a friend who has dropped instead of keeping a stale status.
+        assert_eq!(presence_from_probe(None), FriendPresence::Offline);
+        // A successful Pong with no room is Online.
+        assert_eq!(
+            presence_from_probe(Some((&ControlMsg::Pong { room: None }, friend))),
+            FriendPresence::Online
+        );
+        // A successful Pong advertising the friend's own room is InRoom.
+        let t = valid_ticket(friend);
+        assert_eq!(
+            presence_from_probe(Some((
+                &ControlMsg::Pong {
+                    room: Some(RoomPresence {
+                        name: "Den".into(),
+                        ticket: t.clone()
+                    })
+                },
+                friend,
+            ))),
+            FriendPresence::InRoom {
+                name: "Den".into(),
+                ticket: t
+            }
+        );
+        // A non-reply (a stray Ping) is not a presence -> Offline, never a false Online.
+        assert_eq!(
+            presence_from_probe(Some((&ControlMsg::Ping, friend))),
+            FriendPresence::Offline
+        );
+    }
+
    #[test]
    fn interpret_pong_sanitizes_a_hostile_room_name() {
        // Control/bidi characters in a peer-supplied name are stripped.
        let friend = id();
        let t = valid_ticket(friend);
-        let got = interpret_pong(&ControlMsg::Pong {
-            room: Some(RoomPresence { name: "Hang\u{202e}Out\u{0007}".into(), ticket: t.clone() }),
-        }, friend);
+        let got = interpret_pong(
+            &ControlMsg::Pong {
+                room: Some(RoomPresence {
+                    name: "Hang\u{202e}Out\u{0007}".into(),
+                    ticket: t.clone(),
+                }),
+            },
+            friend,
+        );
        match got {
            Some(FriendPresence::InRoom { name, .. }) => {
                assert!(!name.contains('\u{202e}'), "bidi override must be stripped");
@@ -54,7 +54,10 @@ fn decode(bytes: &[u8]) -> Result<ControlMsg> {
 /// malformed) — the caller treats that as "appears offline". `peer` is usually a
 /// bare [`EndpointId`] (friends store the stable id); a full [`EndpointAddr`] is
 /// also accepted (and used by hermetic tests).
-pub async fn probe(endpoint: &Endpoint, peer: impl Into<EndpointAddr>) -> Result<(EndpointId, ControlMsg)> {
+pub async fn probe(
+    endpoint: &Endpoint,
+    peer: impl Into<EndpointAddr>,
+) -> Result<(EndpointId, ControlMsg)> {
    let conn = tokio::time::timeout(IO_TIMEOUT, endpoint.connect(peer, FRIENDS_ALPN))
        .await
        .context("timed out connecting to peer")?
@@ -62,7 +65,10 @@ pub async fn probe(endpoint: &Endpoint, peer: impl Into<EndpointAddr>) -> Result
    let from = conn.remote_id();

    let io = async {
-        let (mut send, mut recv) = conn.open_bi().await.context("failed to open control stream")?;
+        let (mut send, mut recv) = conn
+            .open_bi()
+            .await
+            .context("failed to open control stream")?;
        send.write_all(&encode(&ControlMsg::Ping)?)
            .await
            .context("failed to write ping")?;
@@ -118,7 +124,10 @@ async fn exchange(conn: &iroh::endpoint::Connection, handler: &Handler) -> Resul

    let io = async {
        let (mut send, mut recv) = conn.accept_bi().await.context("failed to accept stream")?;
-        let bytes = recv.read_to_end(MAX_MSG).await.context("failed to read ping")?;
+        let bytes = recv
+            .read_to_end(MAX_MSG)
+            .await
+            .context("failed to read ping")?;
        match decode(&bytes)? {
            ControlMsg::Ping => {}
            other => bail!("expected a ping, got {other:?}"),
@@ -211,7 +220,10 @@ mod tests {
        let handler: Handler = Arc::new(move |from| {
            if from == allowed {
                Some(ControlMsg::Pong {
-                    room: Some(RoomPresence { name: "HangOut".into(), ticket: "t".into() }),
+                    room: Some(RoomPresence {
+                        name: "HangOut".into(),
+                        ticket: "t".into(),
+                    }),
                })
            } else {
                None // stranger -> no reply
@@ -221,10 +233,11 @@ mod tests {
        let serve_task = tokio::spawn(async move { serve(server_ep, handler).await });

        // The allowed prober gets a Pong with the room.
-        let (from, pong) = tokio::time::timeout(Duration::from_secs(15), probe(&prober, server_addr.clone()))
-            .await
-            .expect("probe timed out")
-            .expect("probe failed");
+        let (from, pong) =
+            tokio::time::timeout(Duration::from_secs(15), probe(&prober, server_addr.clone()))
+                .await
+                .expect("probe timed out")
+                .expect("probe failed");
        assert_eq!(from, server_addr.id);
        match pong {
            ControlMsg::Pong { room: Some(r) } => assert_eq!(r.name, "HangOut"),
@@ -32,7 +32,18 @@ pub const FRIENDS_PROTO: u32 = 1;
 /// strictly required for decoding — but per the versioning discipline a wire-shape
 /// change is isolated into its own topic + signature domain so v2 and v3 peers
 /// never share a swarm. Resync everyone, exactly like the W4 avatar bump.
-pub const GOSSIP_PROTO: u32 = 3;
+///
+/// v4–v5 (0.6.0): the W22 shared-listening / music presence work. `PeerState`
+/// gained an optional `music` presence field (a current shared-listening track
+/// descriptor + playback timeline; the audio bytes still ride the files plane by
+/// id, gossip carries only the descriptor/timeline), and `MusicPresence` then
+/// gained optional prefetch hints for the next track so tuned-in listeners can
+/// fetch it before the DJ advances. Both shipped together in the **0.6.0** release
+/// (commit `bca2ccd`), where the const advanced straight `3 → 5`: there was never
+/// a `GOSSIP_PROTO == 4` build — 4 is a skipped step. (Per `VERSIONING.md` this
+/// breaking gossip change rode the `0.5.1 → 0.6.0` MINOR bump, so the discipline
+/// was honoured; 0.6.1 is a wire-compatible PATCH on top, still proto 5.)
+pub const GOSSIP_PROTO: u32 = 5;
 /// File-transfer plane version (chat attachment request/stream shape). Bump on
 /// any change. Mirrored in [`FILES_ALPN`].
 pub const FILES_PROTO: u32 = 1;
@@ -47,7 +58,7 @@ pub const FILES_ALPN: &[u8] = b"peerspeak/files/1";
 /// ed25519 gossip signature domain: `peerspeak-gossip-v<GOSSIP_PROTO>`. Carries
 /// the gossip protocol version into every signed payload — a version mismatch
 /// fails verification (cryptographic separation between gossip versions).
-pub const GOSSIP_SIG_DOMAIN: &str = "peerspeak-gossip-v3";
+pub const GOSSIP_SIG_DOMAIN: &str = "peerspeak-gossip-v5";

 /// Version-namespace a room topic so peers on different gossip protocol versions
 /// derive **different subscription topics from the same ticket** and therefore
@@ -76,10 +87,22 @@ mod tests {
    /// so a version bump can't silently forget to update the wire string.
    #[test]
    fn alpns_match_their_proto_versions() {
-        assert_eq!(AUDIO_ALPN, format!("peerspeak/audio/{AUDIO_PROTO}").as_bytes());
-        assert_eq!(FRIENDS_ALPN, format!("peerspeak/friends/{FRIENDS_PROTO}").as_bytes());
-        assert_eq!(FILES_ALPN, format!("peerspeak/files/{FILES_PROTO}").as_bytes());
-        assert_eq!(GOSSIP_SIG_DOMAIN, format!("peerspeak-gossip-v{GOSSIP_PROTO}"));
+        assert_eq!(
+            AUDIO_ALPN,
+            format!("peerspeak/audio/{AUDIO_PROTO}").as_bytes()
+        );
+        assert_eq!(
+            FRIENDS_ALPN,
+            format!("peerspeak/friends/{FRIENDS_PROTO}").as_bytes()
+        );
+        assert_eq!(
+            FILES_ALPN,
+            format!("peerspeak/files/{FILES_PROTO}").as_bytes()
+        );
+        assert_eq!(
+            GOSSIP_SIG_DOMAIN,
+            format!("peerspeak-gossip-v{GOSSIP_PROTO}")
+        );
    }

    #[test]
@@ -88,7 +111,11 @@ mod tests {
        let mut b = a;
        b[5] = 10;
        assert_eq!(versioned_topic(a), versioned_topic(a), "deterministic");
-        assert_ne!(versioned_topic(a), versioned_topic(b), "distinct rooms stay distinct");
+        assert_ne!(
+            versioned_topic(a),
+            versioned_topic(b),
+            "distinct rooms stay distinct"
+        );
    }

    #[test]
@@ -51,7 +51,14 @@ fn same_room(a: &str, b: &str) -> bool {
 /// supplies `now` (unix seconds) and persists the list afterwards.
 pub fn push_recent(list: &mut Vec<Recent>, name: String, ticket: String, now: u64) {
    list.retain(|r| !same_room(&r.ticket, &ticket));
-    list.insert(0, Recent { name, ticket, joined_at: now });
+    list.insert(
+        0,
+        Recent {
+            name,
+            ticket,
+            joined_at: now,
+        },
+    );
    list.truncate(RECENTS_MAX);
 }

@@ -86,8 +93,12 @@ mod tests {
    /// Build a real, parseable ticket for a fresh room with the given label.
    fn ticket(name: &str, topic: [u8; 32]) -> String {
        let host = SecretKey::generate().public();
-        PeerSpeakTicket { host_addr: EndpointAddr::from(host), topic_id: topic, name: name.into() }
-            .to_string()
+        PeerSpeakTicket {
+            host_addr: EndpointAddr::from(host),
+            topic_id: topic,
+            name: name.into(),
+        }
+        .to_string()
    }

    #[test]
@@ -85,7 +85,10 @@ pub enum Segment {
 /// Trailing characters commonly adjacent to a URL in prose that should NOT be
 /// part of the link (so "see http://x.com." or "(http://x.com)" linkify cleanly).
 fn is_url_trailing_punct(c: char) -> bool {
-    matches!(c, '.' | ',' | '!' | '?' | ';' | ':' | ')' | ']' | '}' | '>' | '"' | '\'')
+    matches!(
+        c,
+        '.' | ',' | '!' | '?' | ';' | ':' | ')' | ']' | '}' | '>' | '"' | '\''
+    )
 }

 /// Find the byte index of the earliest `http://` or `https://` scheme in `s`,
@@ -144,7 +147,10 @@ mod tests {
    fn strips_control_chars_and_collapses_whitespace() {
        // NUL, CR/LF, TAB, and ANSI ESC are control chars → become spaces, then
        // collapse; ends trim.
-        assert_eq!(sanitize_name("  a\u{0}b\r\nc\td\u{1b}[31m  "), "a b c d [31m");
+        assert_eq!(
+            sanitize_name("  a\u{0}b\r\nc\td\u{1b}[31m  "),
+            "a b c d [31m"
+        );
        // A name that is only control/whitespace cleans to empty.
        assert_eq!(sanitize_name("\u{0}\r\n\t   "), "");
    }
@@ -183,7 +189,10 @@ mod tests {
        let mid = "g".repeat(56);
        assert_eq!(sanitize_game_label(&mid).chars().count(), 56);
        let long = "g".repeat(GAME_LABEL_MAX_CHARS + 100);
-        assert_eq!(sanitize_game_label(&long).chars().count(), GAME_LABEL_MAX_CHARS);
+        assert_eq!(
+            sanitize_game_label(&long).chars().count(),
+            GAME_LABEL_MAX_CHARS
+        );
    }

    #[test]
@@ -220,7 +229,10 @@ mod tests {
    #[test]
    fn linkify_plain_text_has_no_links() {
        let segs = linkify("just a normal message, nothing here");
-        assert_eq!(segs, vec![Segment::Text("just a normal message, nothing here".into())]);
+        assert_eq!(
+            segs,
+            vec![Segment::Text("just a normal message, nothing here".into())]
+        );
    }

    #[test]
@@ -280,7 +292,12 @@ mod tests {
    fn linkify_only_matches_http_schemes() {
        // Non-web schemes and bare domains are NOT linkified (conservative).
        let segs = linkify("email me@x.com or ftp://x.com or visit x.com");
-        assert_eq!(segs, vec![Segment::Text("email me@x.com or ftp://x.com or visit x.com".into())]);
+        assert_eq!(
+            segs,
+            vec![Segment::Text(
+                "email me@x.com or ftp://x.com or visit x.com".into()
+            )]
+        );
    }

    #[test]
@@ -293,7 +310,11 @@ mod tests {
            "weird))) http://c.com]]] tail",
            "unicode 世界 http://d.com/路径 more 世界",
        ] {
-            assert_eq!(reassemble(&linkify(msg)), msg, "roundtrip failed for {msg:?}");
+            assert_eq!(
+                reassemble(&linkify(msg)),
+                msg,
+                "roundtrip failed for {msg:?}"
+            );
        }
    }
 }
@@ -21,6 +21,8 @@ use std::time::Duration;
 use tokio::io::{AsyncBufReadExt, BufReader};
 use tokio::process::{Child, Command};

+use crate::config::{ScreenShareSettings, ShareBuffering, SharePlayer, ShareQuality};
+
 /// The binary we shell out to. Looked up on `$PATH` unless a config override
 /// points elsewhere.
 const PIXELPASS_BIN: &str = "pixelpass";
@@ -39,6 +41,10 @@ fn pixelpass_path_candidates(dir: &Path) -> [PathBuf; 1] {
 /// growth, but reject unbounded gossip payloads before the UI offers "Watch".
 const MAX_TICKET_LEN: usize = 512;

+/// Upper bound on a PipeWire `application.name` we'll pass to `--app`. Real names
+/// are short ("Firefox", "mpv"); this only guards against a pathological value.
+const MAX_APP_NAME_LEN: usize = 256;
+
 /// How long to wait for the host to emit its ticket / the viewer to connect
 /// before giving up and killing the child. Startup is normally sub-second; this
 /// is only a safety net so a hung pixelpass can't wedge the caller forever.
@@ -64,6 +70,12 @@ pub enum PixelpassEvent {
    CaptureStarted,
    /// Host: capture pipeline torn down (on last viewer).
    CaptureStopped,
+    /// Host (per-app audio): the chosen app's audio is now reaching viewers.
+    AppAudioRouted,
+    /// Host (per-app audio): the chosen app's last audio stream went away. Under
+    /// our `--strict-audio` run this means viewers now hear silence (not the call
+    /// echo) until the app produces audio again — we surface it as a warning.
+    AppAudioLost,
    /// A recognized event we don't act on (e.g. `host_info`).
    Other,
 }
@@ -98,6 +110,11 @@ pub fn parse_pixelpass_event(line: &str) -> Option<PixelpassEvent> {
            Some("stopped") => PixelpassEvent::CaptureStopped,
            _ => PixelpassEvent::Other,
        },
+        "app_audio" => match v.get("state").and_then(|s| s.as_str()) {
+            Some("routed") => PixelpassEvent::AppAudioRouted,
+            Some("lost") => PixelpassEvent::AppAudioLost,
+            _ => PixelpassEvent::Other,
+        },
        _ => PixelpassEvent::Other,
    };
    Some(ev)
@@ -107,6 +124,182 @@ fn json_u32(v: &serde_json::Value, key: &str) -> u32 {
    v.get(key).and_then(|x| x.as_u64()).unwrap_or(0) as u32
 }

+/// Build the argv for a pixelpass *host*. Always `--host --output json`; when
+/// `audio_app` is `Some`, append `--app=<name> --strict-audio` so pixelpass
+/// captures only that app's audio instead of the whole desktop sink monitor
+/// (which contains our own call playout → the viewer would hear themselves
+/// echoed back, backlog A23).
+///
+/// `--strict-audio` is what makes the fix a guarantee rather than best-effort:
+/// without it, pixelpass falls back to the whole-desktop loopback before the
+/// app's first stream routes and again if the app's audio later stops — both of
+/// which reintroduce the echo. With it, the viewer hears only the chosen app (or
+/// silence), and pixelpass emits `app_audio` events we surface as a warning.
+///
+/// The name is passed in the single-token `--app=<name>` form so a value that
+/// happens to begin with `-` can never be reparsed as a pixelpass flag (clap
+/// otherwise rejects hyphen-leading option values). The name is locally chosen
+/// (our own enumeration / the user's pick), not peer-supplied, but is still
+/// sanitized via [`sanitize_app_name`] before reaching here. Pure: no I/O.
+pub fn host_args(
+    audio_app: Option<&str>,
+    settings: &ScreenShareSettings,
+    quality: ShareQuality,
+) -> Vec<String> {
+    let mut args = vec![
+        "--host".to_string(),
+        "--output".to_string(),
+        "json".to_string(),
+    ];
+    if let Some(name) = audio_app.and_then(sanitize_app_name) {
+        args.push(format!("--app={name}"));
+        args.push("--strict-audio".to_string());
+    }
+    if quality != ShareQuality::Auto {
+        args.push(format!("--quality={}", pixelpass_quality(quality)));
+    }
+    if let Some(height) = settings.max_height {
+        args.push(format!("--max-height={height}"));
+    }
+    if let Some(mbps) = settings.bitrate_mbps {
+        args.push(format!("--bitrate={}", mbps.saturating_mul(1000)));
+    }
+    if let Some(fps) = settings.framerate {
+        args.push(format!("--framerate={fps}"));
+    }
+    if settings.force_software_encode {
+        args.push("--no-hwencode".to_string());
+    }
+    if let Some(max) = settings.max_viewers {
+        args.push(format!("--max-viewers={max}"));
+    }
+    args.extend(split_extra_args(&settings.extra_host_args));
+    args
+}
+
+fn pixelpass_quality(quality: ShareQuality) -> &'static str {
+    match quality {
+        ShareQuality::Auto => "auto",
+        ShareQuality::Low => "low",
+        ShareQuality::Medium => "medium",
+        ShareQuality::High => "high",
+        ShareQuality::Source => "source",
+    }
+}
+
+/// Split user-supplied advanced argv text into separate tokens. Peerspeak does
+/// not depend on a shell lexer, so quoted values are not interpreted here.
+fn split_extra_args(raw: &str) -> impl Iterator<Item = String> + '_ {
+    raw.split_whitespace().map(str::to_string)
+}
+
+/// Validate a locally-chosen audio app name before it becomes a `--app` value:
+/// trim, reject empty / overlong, and reject names carrying control characters
+/// (newlines etc.) that have no place in a real `application.name`. `None` means
+/// "no valid app selected" — the caller then shares the whole desktop audio.
+pub fn sanitize_app_name(name: &str) -> Option<String> {
+    let name = name.trim();
+    let ok =
+        !name.is_empty() && name.len() <= MAX_APP_NAME_LEN && !name.chars().any(|c| c.is_control());
+    ok.then(|| name.to_string())
+}
+
+/// Hard cap on how long enumeration waits for `pactl`. It runs inline on the core
+/// command loop (the picker awaits it before opening), so a wedged/slow `pactl`
+/// must not stall mute/deafen/leave/stop. On timeout we treat it like any other
+/// failure: empty list → "All system audio" only.
+const LIST_APPS_TIMEOUT: Duration = Duration::from_secs(2);
+
+/// Enumerate the apps currently sending audio to a sink, deduplicated by
+/// `application.name`. Mirrors how pixelpass itself builds its interactive
+/// picker (`pactl -f json list sink-inputs`), so the names we return are exactly
+/// the ones `--app` matches against. Returns an empty list on any error (pactl
+/// missing, non-PipeWire host, nothing playing, or [`LIST_APPS_TIMEOUT`] elapsed)
+/// — a normal, handled state that leaves the picker showing only "All system
+/// audio".
+pub async fn list_audio_apps() -> Vec<String> {
+    let run = Command::new("pactl")
+        .args(["-f", "json", "list", "sink-inputs"])
+        .stdin(Stdio::null())
+        .stdout(Stdio::piped())
+        .stderr(Stdio::null())
+        // On [`LIST_APPS_TIMEOUT`] the `output()` future is dropped, which drops
+        // the child — `kill_on_drop(true)` then SIGKILLs and reaps it so a wedged
+        // `pactl` can't linger/accumulate across picker opens (audit P3).
+        .kill_on_drop(true)
+        .output();
+    match tokio::time::timeout(LIST_APPS_TIMEOUT, run).await {
+        Ok(Ok(o)) if o.status.success() => parse_audio_apps(&o.stdout),
+        _ => Vec::new(),
+    }
+}
+
+/// Hard cap on the capability probe (`pixelpass --help`). Conservative: a slow or
+/// hung pixelpass degrades to "strict audio unsupported" → whole-desktop-only
+/// picker (safe), never a stalled core loop.
+const HELP_PROBE_TIMEOUT: Duration = Duration::from_secs(2);
+
+/// Whether the resolved pixelpass understands `--strict-audio` (added in pixelpass
+/// `85fdebe`). peerspeak only offers per-app audio capture when it does: a per-app
+/// share always appends `--strict-audio`, and an **older** pixelpass would have
+/// clap reject the unknown flag → the host spawn hard-fails and the share is
+/// broken (audit P2, version skew). When unsupported the picker degrades to
+/// whole-desktop audio only — we never silently drop to best-effort `--app`, which
+/// would reintroduce the call echo (A23).
+///
+/// Any probe failure/timeout returns `false` (degrade to the safe path). The
+/// `--help` child is `kill_on_drop` so a hung pixelpass can't linger.
+pub async fn supports_strict_audio(bin: &Path) -> bool {
+    let run = Command::new(bin)
+        .arg("--help")
+        .stdin(Stdio::null())
+        .stdout(Stdio::piped())
+        .stderr(Stdio::null())
+        .kill_on_drop(true)
+        .output();
+    match tokio::time::timeout(HELP_PROBE_TIMEOUT, run).await {
+        Ok(Ok(o)) => help_mentions_strict_audio(&o.stdout),
+        _ => false,
+    }
+}
+
+/// Pure check: does `pixelpass --help` advertise `--strict-audio`? Matches the
+/// flag token rather than a whole line, since clap may wrap/realign help text.
+pub fn help_mentions_strict_audio(help_stdout: &[u8]) -> bool {
+    String::from_utf8_lossy(help_stdout).contains("--strict-audio")
+}
+
+/// Parse `pactl -f json list sink-inputs` stdout into a sorted, deduplicated list
+/// of `application.name`s. Pure: no I/O. Unparseable input yields an empty list.
+/// Each name is passed through [`sanitize_app_name`] so the picker only ever
+/// offers names that will actually survive [`host_args`]; otherwise a name that
+/// parses here but fails sanitization later would be selectable yet silently
+/// drop the `--app` flag and revert the share to whole-desktop audio (A23 echo).
+pub fn parse_audio_apps(stdout: &[u8]) -> Vec<String> {
+    let Ok(entries) = serde_json::from_slice::<Vec<SinkInput>>(stdout) else {
+        return Vec::new();
+    };
+    let mut names: Vec<String> = entries
+        .into_iter()
+        .filter_map(|e| e.properties.application_name)
+        .filter_map(|n| sanitize_app_name(&n))
+        .collect();
+    names.sort_unstable();
+    names.dedup();
+    names
+}
+
+#[derive(serde::Deserialize)]
+struct SinkInput {
+    properties: SinkInputProperties,
+}
+
+#[derive(serde::Deserialize)]
+struct SinkInputProperties {
+    #[serde(rename = "application.name")]
+    application_name: Option<String>,
+}
+
 /// Build the argv for a pixelpass *viewer*. The `ticket` is peer-supplied (it
 /// rides gossip presence, which is untrusted and spoofable), so flags come first
 /// and the ticket is passed as a positional **after a `--` end-of-options
@@ -162,20 +355,37 @@ pub fn is_available(config_override: Option<&str>) -> bool {
    pixelpass_path(config_override).is_some()
 }

-/// Spawn a pixelpass host (`pixelpass --host --output json`), wait for its
-/// startup ticket, and return the live child plus the ticket. The child keeps
+/// Spawn a pixelpass host (`pixelpass --host --output json [--app=<name>]`), wait
+/// for its startup ticket, and return the live child plus the ticket. When
+/// `audio_app` is `Some`, pixelpass captures only that app's audio instead of the
+/// whole desktop sink, which avoids the call-loopback echo (A23). The child keeps
 /// running (streaming to viewers) until killed or dropped; remaining stdout is
 /// drained in a background task so a full pipe can't stall the host. We do
-/// **not** pass `--max-viewers`: pixelpass bandwidth-measures its own safe cap,
-/// protecting the sharer's uplink, and refuses extras with `viewer_refused`.
-pub async fn spawn_host(bin: &Path) -> std::io::Result<(Child, String)> {
+/// not pass encode/viewer overrides unless the local settings explicitly ask for
+/// them, so pixelpass keeps its own defaults in the common case.
+pub async fn spawn_host(
+    bin: &Path,
+    audio_app: Option<&str>,
+    settings: &ScreenShareSettings,
+    quality: ShareQuality,
+    notices: Option<tokio::sync::mpsc::UnboundedSender<PixelpassEvent>>,
+) -> std::io::Result<(Child, String)> {
+    let args = host_args(audio_app, settings, quality);
+    // Log the exact argv we hand pixelpass so a field log can confirm which
+    // encode/quality flags (e.g. --bitrate) actually reached the host — these
+    // are local flags with no ticket/secret, so logging them verbatim is safe.
+    crate::log_msg(&format!("pixelpass host spawn: {} {}", bin.display(), args.join(" ")));
    let mut child = Command::new(bin)
-        .arg("--host")
-        .arg("--output")
-        .arg("json")
+        .args(&args)
        .stdin(Stdio::null())
        .stdout(Stdio::piped())
-        .stderr(Stdio::null())
+        // Capture stderr (not null): pixelpass prints its startup precondition
+        // failures there — a missing GStreamer plugin / `pactl`, each with an
+        // actionable "Install hint: sudo apt install ..." line. If the host dies
+        // before its ticket we fold that tail into our error so the user sees
+        // *what to install* instead of a dead-end "exited before a ticket". On
+        // the success path we drain it in the background so the pipe can't fill.
+        .stderr(Stdio::piped())
        .kill_on_drop(true)
        .spawn()?;

@@ -183,6 +393,7 @@ pub async fn spawn_host(bin: &Path) -> std::io::Result<(Child, String)> {
        .stdout
        .take()
        .ok_or_else(|| std::io::Error::other("pixelpass host stdout missing"))?;
+    let stderr = child.stderr.take();
    let mut lines = BufReader::new(stdout).lines();

    let ticket = match read_until(&mut lines, |e| match e {
@@ -194,9 +405,10 @@ pub async fn spawn_host(bin: &Path) -> std::io::Result<(Child, String)> {
        Ok(Some(t)) => t,
        Ok(None) => {
            let _ = child.kill().await;
-            return Err(std::io::Error::other(
-                "pixelpass host exited before emitting a ticket",
-            ));
+            let detail = read_stderr_tail(stderr).await;
+            return Err(std::io::Error::other(format!(
+                "pixelpass host exited before emitting a ticket{detail}"
+            )));
        }
        Err(e) => {
            let _ = child.kill().await;
@@ -204,15 +416,74 @@ pub async fn spawn_host(bin: &Path) -> std::io::Result<(Child, String)> {
        }
    };

-    drain_in_background(lines, "host");
+    if let Some(stderr) = stderr {
+        drain_stderr_in_background(stderr);
+    }
+    drain_in_background(lines, "host", notices);
    Ok((child, ticket))
 }

+/// Read a killed pixelpass child's stderr to EOF and reduce it to a short,
+/// user-facing diagnostic tail via [`pixelpass_failure_detail`]. Bounded: the
+/// caller kills the child first, so the pipe EOFs promptly. Returns an empty
+/// string when stderr was already taken or carried nothing useful.
+async fn read_stderr_tail(stderr: Option<tokio::process::ChildStderr>) -> String {
+    use tokio::io::AsyncReadExt;
+    let Some(mut stderr) = stderr else {
+        return String::new();
+    };
+    let mut buf = Vec::new();
+    let _ = stderr.read_to_end(&mut buf).await;
+    pixelpass_failure_detail(&String::from_utf8_lossy(&buf))
+}
+
+/// Discard a running pixelpass child's stderr in the background so its pipe
+/// can't fill and stall the host (mirrors [`drain_in_background`] for stdout).
+fn drain_stderr_in_background(mut stderr: tokio::process::ChildStderr) {
+    use tokio::io::AsyncReadExt;
+    tokio::spawn(async move {
+        let mut buf = [0u8; 4096];
+        while let Ok(n) = stderr.read(&mut buf).await {
+            if n == 0 {
+                break;
+            }
+        }
+    });
+}
+
+/// Extract a human-useful tail from a failed pixelpass child's stderr to append
+/// to our error. pixelpass writes actionable startup errors there (a missing
+/// GStreamer element / `pactl` plus an `Install hint: sudo apt install ...`
+/// line), which is exactly what a freshly-installed host needs to see. The
+/// decorative host banner (box-drawing) is dropped — it only prints on the
+/// success path, but we filter it defensively. Pure: no I/O. Returns an empty
+/// string when there's nothing worth surfacing (so callers can append blindly).
+pub fn pixelpass_failure_detail(stderr: &str) -> String {
+    let useful: Vec<&str> = stderr
+        .lines()
+        .map(str::trim_end)
+        .filter(|l| !l.trim().is_empty())
+        .filter(|l| !l.trim_start().starts_with(['│', '┌', '└', '├']))
+        .collect();
+    if useful.is_empty() {
+        return String::new();
+    }
+    // The anyhow error and its install hint are the *last* lines printed, so
+    // keep the tail rather than the head.
+    const MAX_LINES: usize = 12;
+    let start = useful.len().saturating_sub(MAX_LINES);
+    format!("\n\npixelpass reported:\n{}", useful[start..].join("\n"))
+}
+
 /// Spawn a pixelpass viewer for `ticket`, wait for it to connect, and open the
-/// stream in a local player (mpv, falling back to vlc). Returns the live viewer
-/// child so the caller can kill it on room-leave; it also self-exits when the
-/// player window closes (its tunnel ends).
-pub async fn spawn_viewer(bin: &Path, ticket: &str) -> std::io::Result<Child> {
+/// stream in a local player (mpv/VLC in the configured order, then fallback).
+/// Returns the live viewer child so the caller can kill it on room-leave; it also
+/// self-exits when the player window closes (its tunnel ends).
+pub async fn spawn_viewer(
+    bin: &Path,
+    ticket: &str,
+    settings: &ScreenShareSettings,
+) -> std::io::Result<Child> {
    let mut child = Command::new(bin)
        .args(viewer_args(ticket))
        .stdin(Stdio::null())
@@ -246,12 +517,12 @@ pub async fn spawn_viewer(bin: &Path, ticket: &str) -> std::io::Result<Child> {
        }
    };

-    if let Err(e) = launch_player(&url) {
+    if let Err(e) = launch_player(&url, settings) {
        let _ = child.kill().await;
        return Err(e);
    }

-    drain_in_background(lines, "viewer");
+    drain_in_background(lines, "viewer", None);
    Ok(child)
 }

@@ -286,15 +557,24 @@ where
 }

 /// Keep reading the child's stdout to EOF in the background so a full pipe can't
-/// stall it; log notable events for diagnostics.
-fn drain_in_background<R>(mut lines: tokio::io::Lines<BufReader<R>>, role: &'static str)
-where
+/// stall it; log notable events for diagnostics. When `notices` is `Some`, each
+/// parsed event is also forwarded to the caller (the core, which translates the
+/// `app_audio` ones into a UI warning); a send failure (receiver dropped) just
+/// stops forwarding, draining continues. The task ends on EOF (child exited).
+fn drain_in_background<R>(
+    mut lines: tokio::io::Lines<BufReader<R>>,
+    role: &'static str,
+    notices: Option<tokio::sync::mpsc::UnboundedSender<PixelpassEvent>>,
+) where
    R: tokio::io::AsyncRead + Unpin + Send + 'static,
 {
    tokio::spawn(async move {
        while let Ok(Some(line)) = lines.next_line().await {
            if let Some(ev) = parse_pixelpass_event(&line) {
                crate::log_msg(&format!("pixelpass {role}: {}", event_for_log(&ev)));
+                if let Some(tx) = &notices {
+                    let _ = tx.send(ev);
+                }
            }
        }
    });
@@ -313,27 +593,39 @@ fn event_for_log(ev: &PixelpassEvent) -> String {
        PixelpassEvent::Refused(reason) => format!("viewer_refused reason={reason:?}"),
        PixelpassEvent::CaptureStarted => "capture_started".to_string(),
        PixelpassEvent::CaptureStopped => "capture_stopped".to_string(),
+        PixelpassEvent::AppAudioRouted => "app_audio_routed".to_string(),
+        PixelpassEvent::AppAudioLost => "app_audio_lost".to_string(),
        PixelpassEvent::Other => "other".to_string(),
    }
 }

-/// Open the viewer stream URL in a media player. Mirrors pixelpass's own
-/// low-latency mpv invocation; falls back to vlc. The player is reaped in a
-/// background task so it doesn't linger as a zombie when its window closes.
-fn launch_player(url: &str) -> std::io::Result<()> {
-    const MPV_ARGS: &[&str] = &[
-        "--profile=low-latency",
-        "--untimed",
-        "--hwdec=auto",
-        "--audio-buffer=0.2",
-        "--demuxer-max-bytes=2M",
-        "--demuxer-readahead-secs=0.5",
-    ];
-    const VLC_ARGS: &[&str] = &["--network-caching=200", "--live-caching=200"];
+/// Open the viewer stream URL in a media player, then fall back to vlc. The
+/// player is reaped in a background task so it doesn't linger as a zombie when
+/// its window closes.
+///
+/// The flags keep latency low while preserving A/V sync. We deliberately do
+/// NOT pass mpv's `--untimed`: that displays each video frame the instant it
+/// decodes, ignoring audio timestamps, which makes a shared *video* drift
+/// progressively out of sync with its audio. Pacing to the audio clock costs a
+/// little latency (negligible for pointing at a desktop) and keeps a shared
+/// video in sync. We also leave hwdec at the `low-latency` default (software
+/// decode): forcing `--hwdec=auto` froze some viewers on frame 1 while audio
+/// kept playing.
+fn launch_player(url: &str, settings: &ScreenShareSettings) -> std::io::Result<()> {
+    let mpv_args = mpv_args(settings);
+    let vlc_args = vlc_args(settings);
+    let first = match settings.player {
+        SharePlayer::Mpv => ("mpv", &mpv_args),
+        SharePlayer::Vlc => ("vlc", &vlc_args),
+    };
+    let second = match settings.player {
+        SharePlayer::Mpv => ("vlc", &vlc_args),
+        SharePlayer::Vlc => ("mpv", &mpv_args),
+    };

-    let child = match spawn_player("mpv", MPV_ARGS, url) {
+    let child = match spawn_player(first.0, first.1, url) {
        Ok(c) => c,
-        Err(_) => spawn_player("vlc", VLC_ARGS, url).map_err(|_| {
+        Err(_) => spawn_player(second.0, second.1, url).map_err(|_| {
            std::io::Error::new(
                std::io::ErrorKind::NotFound,
                "no media player found — install mpv or vlc to watch screen shares",
@@ -347,7 +639,64 @@ fn launch_player(url: &str) -> std::io::Result<()> {
    Ok(())
 }

-fn spawn_player(bin: &str, args: &[&str], url: &str) -> std::io::Result<Child> {
+pub fn mpv_args(settings: &ScreenShareSettings) -> Vec<String> {
+    let mut args = Vec::new();
+    match settings.buffering {
+        ShareBuffering::LowLatency => {
+            args.push("--profile=low-latency".to_string());
+            args.push("--audio-buffer=0.2".to_string());
+            args.push("--demuxer-readahead-secs=0.5".to_string());
+        }
+        ShareBuffering::Smooth => {
+            args.push("--cache=yes".to_string());
+            args.push("--demuxer-readahead-secs=2".to_string());
+        }
+    }
+    args.push(format!("--demuxer-max-bytes={}M", settings.cache_mb));
+    if settings.hardware_decode {
+        args.push("--hwdec=auto".to_string());
+    }
+    args.extend(split_extra_args(&settings.extra_mpv_args));
+    args
+}
+
+/// Build the argv for a VLC viewer. VLC honors the subset of viewer settings
+/// that map cleanly onto its option set: the buffering posture (network/live
+/// caching, in ms) and hardware decoding. The rest of the viewer knobs are
+/// mpv-specific — `cache_mb` is an mpv demuxer *byte* cache (VLC's caching is
+/// time-based, already covered by `buffering`) and `extra_mpv_args` is literally
+/// mpv flags — so they are deliberately not mapped here; the Settings UI labels
+/// them as mpv-only. Pure: no I/O.
+///
+/// The hardware-decode mapping is the load-bearing one: VLC hardware-decodes by
+/// default, so without an explicit `--avcodec-hw=none` a VLC viewer would ignore
+/// the (default-off) hardware-decode toggle and could hit the frame-1 freeze
+/// that default exists to avoid — the same A-bug that made us drop mpv's forced
+/// `--hwdec=auto`.
+fn vlc_args(settings: &ScreenShareSettings) -> Vec<String> {
+    let caching_ms = match settings.buffering {
+        ShareBuffering::LowLatency => 200,
+        ShareBuffering::Smooth => 1500,
+    };
+    let hw = if settings.hardware_decode {
+        "--avcodec-hw=any"
+    } else {
+        "--avcodec-hw=none"
+    };
+    vec![
+        format!("--network-caching={caching_ms}"),
+        format!("--live-caching={caching_ms}"),
+        hw.to_string(),
+    ]
+}
+
+fn spawn_player(bin: &str, args: &[String], url: &str) -> std::io::Result<Child> {
+    // Log the player + its flags (mpv/vlc, incl. hardware-decode: --hwdec /
+    // --avcodec-hw) so a field log can confirm the viewer settings reached the
+    // player. The `url` is omitted deliberately — it is the local stream address
+    // and is not needed to verify the flags. Logged on each attempt, so a
+    // fallback from the preferred player to the other one is visible too.
+    crate::log_msg(&format!("player spawn: {bin} {}", args.join(" ")));
    Command::new(bin)
        .args(args)
        .arg(url)
@@ -368,7 +717,10 @@ mod tests {
        // i.e. after the `--` end-of-options guard, never parsed as a flag.
        let args = viewer_args("--malicious-flag");
        assert_eq!(args.last().unwrap(), "--malicious-flag", "ticket is last");
-        let guard = args.iter().position(|a| a == "--").expect("`--` guard present");
+        let guard = args
+            .iter()
+            .position(|a| a == "--")
+            .expect("`--` guard present");
        let ticket = args.len() - 1;
        assert!(guard < ticket, "ticket must follow the `--` guard");
        // The real flags are parsed before the guard.
@@ -384,16 +736,290 @@ mod tests {
        );
    }

+    #[test]
+    fn host_args_without_app_shares_whole_desktop() {
+        // No app selected → no --app flag → pixelpass keeps its default
+        // (whole-desktop) audio capture.
+        let settings = ScreenShareSettings::default();
+        assert_eq!(
+            host_args(None, &settings, ShareQuality::Auto),
+            vec!["--host", "--output", "json"]
+        );
+    }
+
+    #[test]
+    fn host_args_with_app_appends_single_token_flag() {
+        // The chosen app rides in the `--app=<name>` single-token form so a
+        // name beginning with `-` can never be reparsed as a flag (A23), plus
+        // `--strict-audio` so pixelpass never falls back to whole-desktop audio.
+        let settings = ScreenShareSettings::default();
+        assert_eq!(
+            host_args(Some("Firefox"), &settings, ShareQuality::Auto),
+            vec![
+                "--host",
+                "--output",
+                "json",
+                "--app=Firefox",
+                "--strict-audio"
+            ]
+        );
+        // The hyphen-leading name is still bound to --app as a single token;
+        // --strict-audio is the trailing flag.
+        let args = host_args(Some("-rm -rf"), &settings, ShareQuality::Auto);
+        assert_eq!(args[3], "--app=-rm -rf");
+        assert_eq!(args[4], "--strict-audio");
+    }
+
+    #[test]
+    fn host_args_blank_or_control_app_is_dropped() {
+        // An empty / whitespace / control-laden selection is sanitized away,
+        // falling back to whole-desktop capture rather than a broken flag.
+        let settings = ScreenShareSettings::default();
+        assert_eq!(
+            host_args(Some("   "), &settings, ShareQuality::Auto),
+            vec!["--host", "--output", "json"]
+        );
+        assert_eq!(
+            host_args(Some("bad\nname"), &settings, ShareQuality::Auto),
+            vec!["--host", "--output", "json"]
+        );
+    }
+
+    #[test]
+    fn host_args_apply_screen_share_settings_and_extra_args_last() {
+        let settings = ScreenShareSettings {
+            bitrate_mbps: Some(5),
+            framerate: Some(60),
+            max_height: Some(1080),
+            max_viewers: Some(4),
+            force_software_encode: true,
+            extra_host_args: "--relay https://relay.example --verbose".to_string(),
+            ..ScreenShareSettings::default()
+        };
+
+        assert_eq!(
+            host_args(Some("Firefox"), &settings, ShareQuality::High),
+            vec![
+                "--host",
+                "--output",
+                "json",
+                "--app=Firefox",
+                "--strict-audio",
+                "--quality=high",
+                "--max-height=1080",
+                "--bitrate=5000",
+                "--framerate=60",
+                "--no-hwencode",
+                "--max-viewers=4",
+                "--relay",
+                "https://relay.example",
+                "--verbose",
+            ]
+        );
+    }
+
+    #[test]
+    fn mpv_args_default_matches_low_latency_software_decode() {
+        assert_eq!(
+            mpv_args(&ScreenShareSettings::default()),
+            vec![
+                "--profile=low-latency",
+                "--audio-buffer=0.2",
+                "--demuxer-readahead-secs=0.5",
+                "--demuxer-max-bytes=2M",
+            ]
+        );
+    }
+
+    #[test]
+    fn mpv_args_smooth_hwdecode_and_extra_args_last() {
+        let settings = ScreenShareSettings {
+            hardware_decode: true,
+            buffering: ShareBuffering::Smooth,
+            cache_mb: 16,
+            extra_mpv_args: "--no-osc --vd-lavc-threads=2".to_string(),
+            ..ScreenShareSettings::default()
+        };
+
+        assert_eq!(
+            mpv_args(&settings),
+            vec![
+                "--cache=yes",
+                "--demuxer-readahead-secs=2",
+                "--demuxer-max-bytes=16M",
+                "--hwdec=auto",
+                "--no-osc",
+                "--vd-lavc-threads=2",
+            ]
+        );
+    }
+
+    #[test]
+    fn vlc_args_default_disables_hardware_decode() {
+        // The A-bug fix default (hardware_decode = false) must reach VLC too:
+        // VLC hardware-decodes by default, so without an explicit
+        // `--avcodec-hw=none` a VLC viewer would ignore the toggle and could hit
+        // the frame-1 freeze. Low-latency buffering keeps the 200 ms caches.
+        assert_eq!(
+            vlc_args(&ScreenShareSettings::default()),
+            vec![
+                "--network-caching=200",
+                "--live-caching=200",
+                "--avcodec-hw=none",
+            ]
+        );
+    }
+
+    #[test]
+    fn vlc_args_smooth_buffering_and_hwdecode() {
+        // Enabling hardware decode flips VLC to `--avcodec-hw=any`; Smooth
+        // buffering raises the network/live caches. cache_mb / extra_mpv_args are
+        // mpv-only and must NOT leak into the VLC argv.
+        let settings = ScreenShareSettings {
+            hardware_decode: true,
+            buffering: ShareBuffering::Smooth,
+            cache_mb: 16,
+            extra_mpv_args: "--no-osc".to_string(),
+            ..ScreenShareSettings::default()
+        };
+        assert_eq!(
+            vlc_args(&settings),
+            vec![
+                "--network-caching=1500",
+                "--live-caching=1500",
+                "--avcodec-hw=any",
+            ]
+        );
+    }
+
+    #[test]
+    fn sanitize_app_name_trims_and_rejects_garbage() {
+        assert_eq!(
+            sanitize_app_name("  Firefox \n"),
+            Some("Firefox".to_string())
+        );
+        assert_eq!(sanitize_app_name(""), None);
+        assert_eq!(sanitize_app_name("   "), None);
+        assert_eq!(sanitize_app_name("a\tb"), None);
+        assert_eq!(sanitize_app_name(&"x".repeat(MAX_APP_NAME_LEN + 1)), None);
+    }
+
+    #[test]
+    fn parse_audio_apps_dedups_and_sorts_by_application_name() {
+        let stdout = br#"[
+            {"index":1,"properties":{"application.name":"Firefox"}},
+            {"index":2,"properties":{"application.name":"mpv"}},
+            {"index":3,"properties":{"application.name":"Firefox"}},
+            {"index":4,"properties":{"application.name":"  Spotify  "}},
+            {"index":5,"properties":{"application.name":""}},
+            {"index":6,"properties":{"other":"no name here"}}
+        ]"#;
+        assert_eq!(
+            parse_audio_apps(stdout),
+            vec![
+                "Firefox".to_string(),
+                "Spotify".to_string(),
+                "mpv".to_string()
+            ]
+        );
+    }
+
+    #[test]
+    fn parse_audio_apps_empty_or_garbage_is_empty() {
+        assert_eq!(parse_audio_apps(b""), Vec::<String>::new());
+        assert_eq!(parse_audio_apps(b"not json"), Vec::<String>::new());
+        assert_eq!(parse_audio_apps(b"[]"), Vec::<String>::new());
+    }
+
+    #[test]
+    fn parse_audio_apps_drops_names_host_args_would_reject() {
+        // Names that parse from pactl but fail `sanitize_app_name` (control chars,
+        // overlong) must NOT be offered in the picker — otherwise the user could
+        // pick one, `host_args` would silently drop `--app`, and the share would
+        // revert to whole-desktop audio (A23 echo) with no signal. The valid name
+        // survives; the control-char and overlong ones are filtered out.
+        let overlong = "x".repeat(MAX_APP_NAME_LEN + 1);
+        let stdout = format!(
+            r#"[
+                {{"index":1,"properties":{{"application.name":"mpv"}}}},
+                {{"index":2,"properties":{{"application.name":"bad\nname"}}}},
+                {{"index":3,"properties":{{"application.name":"{overlong}"}}}}
+            ]"#
+        );
+        assert_eq!(parse_audio_apps(stdout.as_bytes()), vec!["mpv".to_string()]);
+    }
+
+    #[test]
+    fn failure_detail_surfaces_install_hint_and_drops_banner() {
+        // The real shape of a fresh-host failure: anyhow error + install hint on
+        // stderr. We must keep those (so the user knows what to apt install) and
+        // drop the decorative banner box-drawing lines.
+        let stderr = "\
+┌─ PixelPass · host ─────────────────────────────────────────
+│  display server : Wayland
+└────────────────────────────────────────────────────────────
+Error: GStreamer element `vah264enc` not available.
+Install hint: sudo apt install gstreamer1.0-plugins-bad
+";
+        let detail = pixelpass_failure_detail(stderr);
+        assert!(detail.starts_with("\n\npixelpass reported:\n"));
+        assert!(detail.contains("vah264enc` not available"));
+        assert!(detail.contains("sudo apt install gstreamer1.0-plugins-bad"));
+        assert!(!detail.contains('│'), "banner box-drawing must be dropped");
+        assert!(!detail.contains('┌'));
+    }
+
+    #[test]
+    fn failure_detail_empty_when_nothing_useful() {
+        // Blank / banner-only stderr yields an empty string so the caller can
+        // append it to the base message unconditionally without trailing noise.
+        assert_eq!(pixelpass_failure_detail(""), "");
+        assert_eq!(pixelpass_failure_detail("   \n  \n"), "");
+        assert_eq!(
+            pixelpass_failure_detail("│  display server : Wayland\n│  capture : x\n"),
+            ""
+        );
+    }
+
+    #[test]
+    fn failure_detail_keeps_only_the_tail() {
+        // A long stderr is truncated to its last lines (where the real error
+        // and hint live), not its head.
+        let body: String = (0..30).map(|i| format!("line {i}\n")).collect();
+        let detail = pixelpass_failure_detail(&body);
+        assert!(detail.contains("line 29"));
+        assert!(!detail.contains("line 0\n"));
+    }
+
+    #[test]
+    fn help_probe_detects_strict_audio_flag() {
+        // A new pixelpass advertises the flag; an old one doesn't. The probe must
+        // match the token even when clap wraps the option onto its own line.
+        let new_help = b"Options:\n      --app <APP>\n      --strict-audio\n          With --app, never fall back...";
+        assert!(help_mentions_strict_audio(new_help));
+        let old_help = b"Options:\n      --app <APP>\n      --output <OUTPUT>\n  -h, --help";
+        assert!(!help_mentions_strict_audio(old_help));
+        // Garbage / empty output degrades to "unsupported" (safe path).
+        assert!(!help_mentions_strict_audio(b""));
+        assert!(!help_mentions_strict_audio(&[0xff, 0xfe, 0x00]));
+    }
+
    #[test]
    fn sanitize_ticket_accepts_pixelpass_endpoint_ticket_shape() {
        let ticket = "endpointaabwxjexzensznfvuudiapn5tyzws3angd2merarm";
-        assert_eq!(sanitize_ticket(format!("  {ticket}\n")), Some(ticket.to_string()));
+        assert_eq!(
+            sanitize_ticket(format!("  {ticket}\n")),
+            Some(ticket.to_string())
+        );
    }

    #[test]
    fn sanitize_ticket_rejects_oversized_or_garbage_ticket() {
        assert_eq!(sanitize_ticket("not-a-ticket".into()), None);
-        assert_eq!(sanitize_ticket(format!("endpoint{}", "a".repeat(MAX_TICKET_LEN))), None);
+        assert_eq!(
+            sanitize_ticket(format!("endpoint{}", "a".repeat(MAX_TICKET_LEN))),
+            None
+        );
        assert_eq!(sanitize_ticket("endpointabc-def".into()), None);
    }

@@ -417,7 +1043,9 @@ mod tests {
    fn parses_connected_url() {
        assert_eq!(
            parse_pixelpass_event(r#"{"event":"connected","url":"http://127.0.0.1:5500"}"#),
-            Some(PixelpassEvent::Connected("http://127.0.0.1:5500".to_string()))
+            Some(PixelpassEvent::Connected(
+                "http://127.0.0.1:5500".to_string()
+            ))
        );
    }

@@ -470,6 +1098,29 @@ mod tests {
        );
    }

+    #[test]
+    fn parses_app_audio_states() {
+        // The wire contract from pixelpass's --strict-audio run (A23): routed =
+        // the chosen app's audio is live; lost = it stopped (viewers now silent).
+        assert_eq!(
+            parse_pixelpass_event(r#"{"event":"app_audio","state":"routed"}"#),
+            Some(PixelpassEvent::AppAudioRouted)
+        );
+        assert_eq!(
+            parse_pixelpass_event(r#"{"event":"app_audio","state":"lost"}"#),
+            Some(PixelpassEvent::AppAudioLost)
+        );
+        // Unknown / missing state is recognized-but-unused, not a parse failure.
+        assert_eq!(
+            parse_pixelpass_event(r#"{"event":"app_audio","state":"weird"}"#),
+            Some(PixelpassEvent::Other)
+        );
+        assert_eq!(
+            parse_pixelpass_event(r#"{"event":"app_audio"}"#),
+            Some(PixelpassEvent::Other)
+        );
+    }
+
    #[test]
    fn recognized_but_unused_event_is_other() {
        assert_eq!(
@@ -529,7 +1180,10 @@ mod tests {
        let dir = Path::new("bin");
        let candidates: Vec<PathBuf> = pixelpass_path_candidates(dir).into_iter().collect();
        #[cfg(windows)]
-        assert_eq!(candidates, vec![dir.join("pixelpass"), dir.join("pixelpass.exe")]);
+        assert_eq!(
+            candidates,
+            vec![dir.join("pixelpass"), dir.join("pixelpass.exe")]
+        );
        #[cfg(not(windows))]
        assert_eq!(candidates, vec![dir.join("pixelpass")]);
    }
@@ -211,7 +211,7 @@ impl AppTheme {
                overlay: hex(0x6272a4),
                text: hex(0xf8f8f2),
                subtext: hex(0xbdc0d4),
-                blue: hex(0xbd93f9),  // Dracula's signature purple as the primary accent
+                blue: hex(0xbd93f9), // Dracula's signature purple as the primary accent
                lavender: hex(0x8be9fd), // cyan
                red: hex(0xff5555),
                maroon: hex(0xff79c6), // pink
@@ -400,7 +400,11 @@ mod tests {
        for theme in AppTheme::ALL {
            let p = theme.palette();
            let sub = contrast_ratio(p.subtext, p.base);
-            assert!(sub >= 3.0, "{}: subtext contrast {sub:.2} < 3.0", theme.label());
+            assert!(
+                sub >= 3.0,
+                "{}: subtext contrast {sub:.2} < 3.0",
+                theme.label()
+            );
            let accent = contrast_ratio(p.blue, p.base);
            assert!(
                accent >= 3.0,
@@ -0,0 +1,992 @@
+use iced::advanced::clipboard::{self, Clipboard};
+use iced::advanced::layout;
+use iced::advanced::mouse;
+use iced::advanced::overlay;
+use iced::advanced::renderer;
+use iced::advanced::text;
+use iced::advanced::widget::tree::{self, Tree};
+use iced::advanced::widget::{self, Widget};
+use iced::advanced::{Layout, Shell};
+use iced::widget::text_input;
+use iced::{
+    Background, Border, Color, Element, Event, Length, Padding, Pixels, Point, Rectangle, Shadow,
+    Size, Vector, alignment,
+};
+use std::rc::Rc;
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct Edit {
+    pub value: String,
+    pub cursor: usize,
+}
+
+pub fn copy_selection(value: &str, start: usize, end: usize) -> Option<String> {
+    let value = text_input::Value::new(value);
+    let (start, end) = normalized_range(&value, start, end);
+
+    (start != end).then(|| value.select(start, end).to_string())
+}
+
+pub fn cut_selection(value: &str, start: usize, end: usize) -> (Edit, Option<String>) {
+    let mut value = text_input::Value::new(value);
+    let (start, end) = normalized_range(&value, start, end);
+
+    if start == end {
+        return (
+            Edit {
+                value: value.to_string(),
+                cursor: start,
+            },
+            None,
+        );
+    }
+
+    let selected = value.select(start, end).to_string();
+    value.remove_many(start, end);
+
+    (
+        Edit {
+            value: value.to_string(),
+            cursor: start,
+        },
+        Some(selected),
+    )
+}
+
+pub fn paste(value: &str, start: usize, end: usize, clip: &str) -> Edit {
+    let mut value = text_input::Value::new(value);
+    let (start, end) = normalized_range(&value, start, end);
+    let clip = text_input::Value::new(clip);
+    let cursor = start + clip.len();
+
+    if start != end {
+        value.remove_many(start, end);
+    }
+    value.insert_many(start, clip);
+
+    Edit {
+        value: value.to_string(),
+        cursor,
+    }
+}
+
+/// Strip control characters (e.g. a trailing newline on an X11 PRIMARY
+/// selection) from clipboard text before it is pasted. Shared by the
+/// right-click menu Paste and the middle-click PRIMARY paste.
+pub fn sanitize_clip(raw: &str) -> String {
+    raw.chars().filter(|c| !c.is_control()).collect()
+}
+
+pub fn select_all_range(value: &str) -> (usize, usize) {
+    let value = text_input::Value::new(value);
+
+    (0, value.len())
+}
+
+fn normalized_range(value: &text_input::Value, start: usize, end: usize) -> (usize, usize) {
+    let len = value.len();
+
+    (start.min(end).min(len), start.max(end).min(len))
+}
+
+type InputStyleFn<'a, Theme> = Rc<dyn Fn(&Theme, text_input::Status) -> text_input::Style + 'a>;
+
+pub fn context_input<'a, Message, Theme, Renderer>(
+    placeholder: &str,
+    value: &str,
+) -> ContextInput<'a, Message, Theme, Renderer>
+where
+    Message: Clone + 'a,
+    Theme: text_input::Catalog + 'a,
+    Renderer: text::Renderer,
+{
+    ContextInput::new(placeholder, value)
+}
+
+pub fn locked_value<'a, Message, Theme, Renderer>(
+    value: &str,
+    noop: Message,
+) -> ContextInput<'a, Message, Theme, Renderer>
+where
+    Message: Clone + 'a,
+    Theme: text_input::Catalog + 'a,
+    Renderer: text::Renderer,
+{
+    ContextInput::new("", value)
+        .on_input(move |_| noop.clone())
+        .locked(true)
+}
+
+pub struct ContextInput<'a, Message, Theme = iced::Theme, Renderer = iced::Renderer>
+where
+    Theme: text_input::Catalog,
+    Renderer: text::Renderer,
+{
+    input: text_input::TextInput<'a, Message, Theme, Renderer>,
+    value: String,
+    is_secure: bool,
+    locked: bool,
+    on_input: Option<Rc<dyn Fn(String) -> Message + 'a>>,
+    on_paste: Option<Rc<dyn Fn(String) -> Message + 'a>>,
+    style: Option<InputStyleFn<'a, Theme>>,
+}
+
+impl<'a, Message, Theme, Renderer> ContextInput<'a, Message, Theme, Renderer>
+where
+    Message: Clone + 'a,
+    Theme: text_input::Catalog + 'a,
+    Renderer: text::Renderer,
+{
+    pub fn new(placeholder: &str, value: &str) -> Self {
+        Self {
+            input: text_input::TextInput::new(placeholder, value),
+            value: value.to_owned(),
+            is_secure: false,
+            locked: false,
+            on_input: None,
+            on_paste: None,
+            style: None,
+        }
+    }
+
+    pub fn id(mut self, id: impl Into<widget::Id>) -> Self {
+        self.input = self.input.id(id);
+        self
+    }
+
+    pub fn secure(mut self, is_secure: bool) -> Self {
+        self.is_secure = is_secure;
+        self.input = self.input.secure(is_secure);
+        self
+    }
+
+    pub fn locked(mut self, yes: bool) -> Self {
+        self.locked = yes;
+        self
+    }
+
+    pub fn on_input(mut self, on_input: impl Fn(String) -> Message + 'a) -> Self {
+        let on_input: Rc<dyn Fn(String) -> Message + 'a> = Rc::new(on_input);
+        let input_callback = Rc::clone(&on_input);
+
+        self.input = self
+            .input
+            .on_input(move |value| input_callback.as_ref()(value));
+        self.on_input = Some(on_input);
+        self
+    }
+
+    pub fn on_submit(mut self, message: Message) -> Self {
+        self.input = self.input.on_submit(message);
+        self
+    }
+
+    pub fn on_submit_maybe(mut self, message: Option<Message>) -> Self {
+        self.input = self.input.on_submit_maybe(message);
+        self
+    }
+
+    pub fn on_paste(mut self, on_paste: impl Fn(String) -> Message + 'a) -> Self {
+        let on_paste: Rc<dyn Fn(String) -> Message + 'a> = Rc::new(on_paste);
+        let paste_callback = Rc::clone(&on_paste);
+
+        self.input = self
+            .input
+            .on_paste(move |value| paste_callback.as_ref()(value));
+        self.on_paste = Some(on_paste);
+        self
+    }
+
+    pub fn font(mut self, font: Renderer::Font) -> Self {
+        self.input = self.input.font(font);
+        self
+    }
+
+    pub fn icon(mut self, icon: text_input::Icon<Renderer::Font>) -> Self {
+        self.input = self.input.icon(icon);
+        self
+    }
+
+    pub fn width(mut self, width: impl Into<Length>) -> Self {
+        self.input = self.input.width(width);
+        self
+    }
+
+    pub fn padding<P: Into<Padding>>(mut self, padding: P) -> Self {
+        self.input = self.input.padding(padding);
+        self
+    }
+
+    pub fn size(mut self, size: impl Into<Pixels>) -> Self {
+        self.input = self.input.size(size);
+        self
+    }
+
+    pub fn line_height(mut self, line_height: impl Into<text::LineHeight>) -> Self {
+        self.input = self.input.line_height(line_height);
+        self
+    }
+
+    pub fn align_x(mut self, alignment: impl Into<alignment::Horizontal>) -> Self {
+        self.input = self.input.align_x(alignment);
+        self
+    }
+
+    pub fn style(
+        mut self,
+        style: impl Fn(&Theme, text_input::Status) -> text_input::Style + 'a,
+    ) -> Self
+    where
+        Theme::Class<'a>: From<text_input::StyleFn<'a, Theme>>,
+    {
+        let style: InputStyleFn<'a, Theme> = Rc::new(style);
+        let input_style = Rc::clone(&style);
+
+        self.input = self
+            .input
+            .style(move |theme, status| input_style.as_ref()(theme, status));
+        self.style = Some(style);
+        self
+    }
+
+    pub fn class(mut self, class: impl Into<Theme::Class<'a>>) -> Self {
+        self.input = self.input.class(class);
+        self.style = None;
+        self
+    }
+}
+
+#[derive(Default)]
+struct ContextInputState {
+    menu: Option<MenuState>,
+}
+
+#[derive(Debug, Clone, Copy)]
+struct MenuState {
+    anchor: Point,
+    selection: (usize, usize),
+}
+
+impl<Message, Theme, Renderer> Widget<Message, Theme, Renderer>
+    for ContextInput<'_, Message, Theme, Renderer>
+where
+    Message: Clone,
+    Theme: text_input::Catalog,
+    Renderer: text::Renderer,
+{
+    fn tag(&self) -> tree::Tag {
+        tree::Tag::of::<ContextInputState>()
+    }
+
+    fn state(&self) -> tree::State {
+        tree::State::new(ContextInputState::default())
+    }
+
+    fn children(&self) -> Vec<Tree> {
+        vec![Tree::new(&self.input as &dyn Widget<_, _, _>)]
+    }
+
+    fn diff(&self, tree: &mut Tree) {
+        if tree.children.is_empty() {
+            tree.children
+                .push(Tree::new(&self.input as &dyn Widget<_, _, _>));
+        } else {
+            tree.children[0].diff(&self.input as &dyn Widget<_, _, _>);
+            tree.children.truncate(1);
+        }
+    }
+
+    fn size(&self) -> Size<Length> {
+        Widget::size(&self.input)
+    }
+
+    fn size_hint(&self) -> Size<Length> {
+        Widget::size_hint(&self.input)
+    }
+
+    fn layout(
+        &mut self,
+        tree: &mut Tree,
+        renderer: &Renderer,
+        limits: &layout::Limits,
+    ) -> layout::Node {
+        Widget::layout(&mut self.input, &mut tree.children[0], renderer, limits)
+    }
+
+    fn operate(
+        &mut self,
+        tree: &mut Tree,
+        layout: Layout<'_>,
+        renderer: &Renderer,
+        operation: &mut dyn widget::Operation,
+    ) {
+        Widget::operate(
+            &mut self.input,
+            &mut tree.children[0],
+            layout,
+            renderer,
+            operation,
+        );
+    }
+
+    fn update(
+        &mut self,
+        tree: &mut Tree,
+        event: &Event,
+        layout: Layout<'_>,
+        cursor: mouse::Cursor,
+        renderer: &Renderer,
+        clipboard: &mut dyn Clipboard,
+        shell: &mut Shell<'_, Message>,
+        viewport: &Rectangle,
+    ) {
+        let right_click_on_input = matches!(
+            event,
+            Event::Mouse(mouse::Event::ButtonPressed(mouse::Button::Right))
+        ) && cursor.is_over(layout.bounds());
+
+        if right_click_on_input {
+            let value = text_input::Value::new(&self.value);
+            let input_state = tree.children[0]
+                .state
+                .downcast_ref::<text_input::State<Renderer::Paragraph>>();
+            let selection = match input_state.cursor().state(&value) {
+                text_input::cursor::State::Index(index) => {
+                    let index = index.min(value.len());
+                    (index, index)
+                }
+                text_input::cursor::State::Selection { start, end } => {
+                    normalized_range(&value, start, end)
+                }
+            };
+
+            tree.state.downcast_mut::<ContextInputState>().menu = cursor
+                .position()
+                .map(|anchor| MenuState { anchor, selection });
+
+            shell.capture_event();
+            shell.request_redraw();
+            return;
+        }
+
+        // Middle-click pastes the X11 PRIMARY selection at the cursor. iced's
+        // base text_input only wires Ctrl+V to the Standard (CLIPBOARD)
+        // selection, so without this the common "select text, middle-click to
+        // paste" workflow does nothing on X11.
+        let middle_click_on_input = matches!(
+            event,
+            Event::Mouse(mouse::Event::ButtonPressed(mouse::Button::Middle))
+        ) && cursor.is_over(layout.bounds());
+
+        if middle_click_on_input && !self.locked {
+            let clip = sanitize_clip(&clipboard.read(clipboard::Kind::Primary).unwrap_or_default());
+
+            if !clip.is_empty() {
+                let value = text_input::Value::new(&self.value);
+                let input_state = tree.children[0]
+                    .state
+                    .downcast_mut::<text_input::State<Renderer::Paragraph>>();
+                let (start, end) = match input_state.cursor().state(&value) {
+                    text_input::cursor::State::Index(index) => {
+                        let index = index.min(value.len());
+                        (index, index)
+                    }
+                    text_input::cursor::State::Selection { start, end } => {
+                        normalized_range(&value, start, end)
+                    }
+                };
+
+                let edit = paste(&self.value, start, end, &clip);
+                input_state.move_cursor_to(edit.cursor);
+
+                if let Some(on_paste) = &self.on_paste {
+                    shell.publish(on_paste.as_ref()(edit.value));
+                } else if let Some(on_input) = &self.on_input {
+                    shell.publish(on_input.as_ref()(edit.value));
+                }
+            }
+
+            shell.capture_event();
+            shell.request_redraw();
+            return;
+        }
+
+        Widget::update(
+            &mut self.input,
+            &mut tree.children[0],
+            event,
+            layout,
+            cursor,
+            renderer,
+            clipboard,
+            shell,
+            viewport,
+        );
+    }
+
+    fn draw(
+        &self,
+        tree: &Tree,
+        renderer: &mut Renderer,
+        theme: &Theme,
+        style: &renderer::Style,
+        layout: Layout<'_>,
+        cursor: mouse::Cursor,
+        viewport: &Rectangle,
+    ) {
+        Widget::draw(
+            &self.input,
+            &tree.children[0],
+            renderer,
+            theme,
+            style,
+            layout,
+            cursor,
+            viewport,
+        );
+    }
+
+    fn mouse_interaction(
+        &self,
+        tree: &Tree,
+        layout: Layout<'_>,
+        cursor: mouse::Cursor,
+        viewport: &Rectangle,
+        renderer: &Renderer,
+    ) -> mouse::Interaction {
+        Widget::mouse_interaction(
+            &self.input,
+            &tree.children[0],
+            layout,
+            cursor,
+            viewport,
+            renderer,
+        )
+    }
+
+    fn overlay<'a>(
+        &'a mut self,
+        tree: &'a mut Tree,
+        _layout: Layout<'a>,
+        _renderer: &Renderer,
+        _viewport: &Rectangle,
+        _translation: Vector,
+    ) -> Option<overlay::Element<'a, Message, Theme, Renderer>> {
+        let Tree {
+            state, children, ..
+        } = tree;
+        let menu = &mut state.downcast_mut::<ContextInputState>().menu;
+
+        if menu.is_none() {
+            return None;
+        }
+
+        let input_state = children[0]
+            .state
+            .downcast_mut::<text_input::State<Renderer::Paragraph>>();
+
+        Some(overlay::Element::new(Box::new(ContextMenuOverlay {
+            menu,
+            input_state,
+            value: &self.value,
+            is_secure: self.is_secure,
+            locked: self.locked,
+            on_input: self.on_input.clone(),
+            on_paste: self.on_paste.clone(),
+            style: self.style.clone(),
+        })))
+    }
+}
+
+impl<'a, Message, Theme, Renderer> From<ContextInput<'a, Message, Theme, Renderer>>
+    for Element<'a, Message, Theme, Renderer>
+where
+    Message: Clone + 'a,
+    Theme: text_input::Catalog + 'a,
+    Renderer: text::Renderer + 'a,
+{
+    fn from(
+        input: ContextInput<'a, Message, Theme, Renderer>,
+    ) -> Element<'a, Message, Theme, Renderer> {
+        Element::new(input)
+    }
+}
+
+struct ContextMenuOverlay<'a, Message, Theme, Renderer>
+where
+    Theme: text_input::Catalog,
+    Renderer: text::Renderer,
+{
+    menu: &'a mut Option<MenuState>,
+    input_state: &'a mut text_input::State<Renderer::Paragraph>,
+    value: &'a str,
+    is_secure: bool,
+    locked: bool,
+    on_input: Option<Rc<dyn Fn(String) -> Message + 'a>>,
+    on_paste: Option<Rc<dyn Fn(String) -> Message + 'a>>,
+    style: Option<InputStyleFn<'a, Theme>>,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+enum MenuAction {
+    Cut,
+    Copy,
+    Paste,
+    SelectAll,
+}
+
+impl MenuAction {
+    const ALL: [Self; 4] = [Self::Cut, Self::Copy, Self::Paste, Self::SelectAll];
+
+    fn label(self) -> &'static str {
+        match self {
+            Self::Cut => "Cut",
+            Self::Copy => "Copy",
+            Self::Paste => "Paste",
+            Self::SelectAll => "Select All",
+        }
+    }
+}
+
+const MENU_WIDTH: f32 = 136.0;
+const ITEM_HEIGHT: f32 = 28.0;
+const TEXT_SIZE: f32 = 13.0;
+const MENU_PADDING_X: f32 = 10.0;
+
+impl<Message, Theme, Renderer> overlay::Overlay<Message, Theme, Renderer>
+    for ContextMenuOverlay<'_, Message, Theme, Renderer>
+where
+    Theme: text_input::Catalog,
+    Renderer: text::Renderer,
+{
+    fn layout(&mut self, _renderer: &Renderer, bounds: Size) -> layout::Node {
+        let size = Size::new(MENU_WIDTH, ITEM_HEIGHT * MenuAction::ALL.len() as f32);
+        let Some(menu) = self.menu.as_ref() else {
+            return layout::Node::new(Size::ZERO);
+        };
+        let x = menu.anchor.x.min((bounds.width - size.width).max(0.0));
+        let y = menu.anchor.y.min((bounds.height - size.height).max(0.0));
+
+        layout::Node::new(size).move_to(Point::new(x.max(0.0), y.max(0.0)))
+    }
+
+    fn draw(
+        &self,
+        renderer: &mut Renderer,
+        theme: &Theme,
+        _style: &renderer::Style,
+        layout: Layout<'_>,
+        cursor: mouse::Cursor,
+    ) {
+        let active_style = input_style(theme, self.style.as_ref(), text_input::Status::Active);
+        let hovered_style = input_style(theme, self.style.as_ref(), text_input::Status::Hovered);
+        let bounds = layout.bounds();
+        let viewport = Rectangle::INFINITE;
+
+        renderer.fill_quad(
+            renderer::Quad {
+                bounds,
+                border: Border {
+                    radius: 5.0.into(),
+                    width: 1.0,
+                    color: active_style.border.color,
+                },
+                shadow: Shadow {
+                    color: Color::from_rgba(0.0, 0.0, 0.0, 0.22),
+                    offset: Vector::new(0.0, 4.0),
+                    blur_radius: 10.0,
+                },
+                ..renderer::Quad::default()
+            },
+            active_style.background,
+        );
+
+        for (index, action) in MenuAction::ALL.iter().copied().enumerate() {
+            let item_bounds = item_bounds(bounds, index);
+            let enabled = self.enabled(action);
+            let hovered = enabled && cursor.is_over(item_bounds);
+
+            if hovered {
+                renderer.fill_quad(
+                    renderer::Quad {
+                        bounds: item_bounds,
+                        border: Border {
+                            radius: 3.0.into(),
+                            ..Border::default()
+                        },
+                        ..renderer::Quad::default()
+                    },
+                    Background::Color(hovered_style.selection),
+                );
+            }
+
+            renderer.fill_text(
+                text::Text {
+                    content: action.label().to_owned(),
+                    bounds: Size::new(item_bounds.width - MENU_PADDING_X * 2.0, item_bounds.height),
+                    size: Pixels(TEXT_SIZE),
+                    line_height: text::LineHeight::default(),
+                    font: renderer.default_font(),
+                    align_x: text::Alignment::Default,
+                    align_y: alignment::Vertical::Center,
+                    shaping: text::Shaping::Advanced,
+                    wrapping: text::Wrapping::default(),
+                },
+                Point::new(item_bounds.x + MENU_PADDING_X, item_bounds.center_y()),
+                if enabled {
+                    active_style.value
+                } else {
+                    disabled_color(active_style.value)
+                },
+                viewport,
+            );
+        }
+    }
+
+    fn update(
+        &mut self,
+        event: &Event,
+        layout: Layout<'_>,
+        cursor: mouse::Cursor,
+        _renderer: &Renderer,
+        clipboard: &mut dyn Clipboard,
+        shell: &mut Shell<'_, Message>,
+    ) {
+        match event {
+            Event::Keyboard(iced::keyboard::Event::KeyPressed {
+                key: iced::keyboard::Key::Named(iced::keyboard::key::Named::Escape),
+                ..
+            }) => {
+                self.close(shell);
+            }
+            Event::Mouse(mouse::Event::ButtonPressed(mouse::Button::Left)) => {
+                let Some(position) = cursor.position() else {
+                    self.close(shell);
+                    return;
+                };
+                let bounds = layout.bounds();
+
+                if !bounds.contains(position) {
+                    self.close(shell);
+                    return;
+                }
+
+                if let Some(action) = self.hit_action(bounds, position) {
+                    if self.enabled(action) {
+                        self.perform(action, clipboard, shell);
+                    }
+                    self.close(shell);
+                }
+            }
+            Event::Mouse(mouse::Event::ButtonPressed(_)) => {
+                let should_close = cursor
+                    .position()
+                    .is_none_or(|position| !layout.bounds().contains(position));
+
+                if should_close {
+                    self.close(shell);
+                }
+            }
+            _ => {}
+        }
+    }
+
+    fn mouse_interaction(
+        &self,
+        layout: Layout<'_>,
+        cursor: mouse::Cursor,
+        _renderer: &Renderer,
+    ) -> mouse::Interaction {
+        let Some(position) = cursor.position() else {
+            return mouse::Interaction::default();
+        };
+
+        if self.hit_action(layout.bounds(), position).is_some() {
+            mouse::Interaction::Pointer
+        } else {
+            mouse::Interaction::default()
+        }
+    }
+}
+
+impl<Message, Theme, Renderer> ContextMenuOverlay<'_, Message, Theme, Renderer>
+where
+    Theme: text_input::Catalog,
+    Renderer: text::Renderer,
+{
+    fn enabled(&self, action: MenuAction) -> bool {
+        let Some(menu) = self.menu.as_ref() else {
+            return false;
+        };
+        let has_selection = menu.selection.0 != menu.selection.1;
+        let has_value = !text_input::Value::new(self.value).is_empty();
+
+        menu_action_enabled(
+            action,
+            has_selection,
+            has_value,
+            self.is_secure,
+            self.locked,
+        )
+    }
+
+    fn hit_action(&self, bounds: Rectangle, position: Point) -> Option<MenuAction> {
+        if !bounds.contains(position) {
+            return None;
+        }
+
+        let index = ((position.y - bounds.y) / ITEM_HEIGHT).floor() as usize;
+
+        MenuAction::ALL.get(index).copied()
+    }
+
+    fn perform(
+        &mut self,
+        action: MenuAction,
+        clipboard: &mut dyn Clipboard,
+        shell: &mut Shell<'_, Message>,
+    ) {
+        let Some(menu) = self.menu.as_ref().copied() else {
+            return;
+        };
+        let (start, end) = menu.selection;
+
+        match action {
+            MenuAction::Cut => {
+                let (edit, selected) = cut_selection(self.value, start, end);
+
+                if let Some(selected) = selected {
+                    clipboard.write(clipboard::Kind::Standard, selected);
+                    self.publish_edit(edit, shell);
+                }
+            }
+            MenuAction::Copy => {
+                if let Some(selected) = copy_selection(self.value, start, end) {
+                    clipboard.write(clipboard::Kind::Standard, selected);
+                }
+            }
+            MenuAction::Paste => {
+                let clip = sanitize_clip(&clipboard.read(clipboard::Kind::Standard).unwrap_or_default());
+                let edit = paste(self.value, start, end, &clip);
+
+                self.publish_paste(edit, shell);
+            }
+            MenuAction::SelectAll => {
+                let (start, end) = select_all_range(self.value);
+
+                self.input_state.select_range(start, end);
+                shell.request_redraw();
+            }
+        }
+    }
+
+    fn publish_edit(&mut self, edit: Edit, shell: &mut Shell<'_, Message>) {
+        if let Some(on_input) = &self.on_input {
+            self.input_state.move_cursor_to(edit.cursor);
+            shell.publish(on_input.as_ref()(edit.value));
+            shell.request_redraw();
+        }
+    }
+
+    fn publish_paste(&mut self, edit: Edit, shell: &mut Shell<'_, Message>) {
+        self.input_state.move_cursor_to(edit.cursor);
+
+        if let Some(on_paste) = &self.on_paste {
+            shell.publish(on_paste.as_ref()(edit.value));
+        } else if let Some(on_input) = &self.on_input {
+            shell.publish(on_input.as_ref()(edit.value));
+        }
+
+        shell.request_redraw();
+    }
+
+    fn close(&mut self, shell: &mut Shell<'_, Message>) {
+        *self.menu = None;
+        shell.capture_event();
+        shell.request_redraw();
+    }
+}
+
+fn item_bounds(menu_bounds: Rectangle, index: usize) -> Rectangle {
+    Rectangle {
+        x: menu_bounds.x + 3.0,
+        y: menu_bounds.y + 3.0 + ITEM_HEIGHT * index as f32,
+        width: menu_bounds.width - 6.0,
+        height: ITEM_HEIGHT,
+    }
+}
+
+fn input_style<Theme: text_input::Catalog>(
+    theme: &Theme,
+    style: Option<&InputStyleFn<'_, Theme>>,
+    status: text_input::Status,
+) -> text_input::Style {
+    if let Some(style) = style {
+        style.as_ref()(theme, status)
+    } else {
+        let class = <Theme as text_input::Catalog>::default();
+
+        theme.style(&class, status)
+    }
+}
+
+fn disabled_color(color: Color) -> Color {
+    Color {
+        a: color.a * 0.45,
+        ..color
+    }
+}
+
+fn menu_action_enabled(
+    action: MenuAction,
+    has_selection: bool,
+    has_value: bool,
+    is_secure: bool,
+    locked: bool,
+) -> bool {
+    match action {
+        MenuAction::Cut => has_selection && !is_secure && !locked,
+        MenuAction::Copy => has_selection && !is_secure,
+        MenuAction::Paste => !locked,
+        MenuAction::SelectAll => has_value,
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn copy_selection_returns_middle_substring_and_empty_none() {
+        assert_eq!(copy_selection("abcdef", 2, 5), Some("cde".to_owned()));
+        assert_eq!(copy_selection("abcdef", 3, 3), None);
+    }
+
+    #[test]
+    fn cut_selection_removes_range_and_copies_selection() {
+        let (edit, clip) = cut_selection("abcdef", 2, 5);
+
+        assert_eq!(
+            edit,
+            Edit {
+                value: "abf".to_owned(),
+                cursor: 2,
+            }
+        );
+        assert_eq!(clip, Some("cde".to_owned()));
+
+        let (edit, clip) = cut_selection("abcdef", 3, 3);
+        assert_eq!(
+            edit,
+            Edit {
+                value: "abcdef".to_owned(),
+                cursor: 3,
+            }
+        );
+        assert_eq!(clip, None);
+    }
+
+    #[test]
+    fn sanitize_clip_strips_control_chars_keeps_text() {
+        // An X11 PRIMARY selection commonly carries a trailing newline.
+        assert_eq!(sanitize_clip("pixelpassF1:abc\n"), "pixelpassF1:abc");
+        assert_eq!(sanitize_clip("a\tb\r\nc"), "abc");
+        // Non-control unicode is preserved.
+        assert_eq!(sanitize_clip("héllo🦀"), "héllo🦀");
+        assert_eq!(sanitize_clip(""), "");
+    }
+
+    #[test]
+    fn paste_replaces_selection_or_inserts_at_cursor() {
+        assert_eq!(
+            paste("abcdef", 2, 5, "XY"),
+            Edit {
+                value: "abXYf".to_owned(),
+                cursor: 4,
+            }
+        );
+        assert_eq!(
+            paste("abcdef", 3, 3, "XY"),
+            Edit {
+                value: "abcXYdef".to_owned(),
+                cursor: 5,
+            }
+        );
+    }
+
+    #[test]
+    fn select_all_range_uses_grapheme_length() {
+        assert_eq!(select_all_range(""), (0, 0));
+        assert_eq!(select_all_range("abé🦀"), (0, 4));
+    }
+
+    #[test]
+    fn unicode_selection_boundaries_are_grapheme_correct() {
+        assert_eq!(copy_selection("aé🦀z", 1, 3), Some("é🦀".to_owned()));
+
+        let (edit, clip) = cut_selection("aé🦀z", 2, 3);
+        assert_eq!(clip, Some("🦀".to_owned()));
+        assert_eq!(
+            edit,
+            Edit {
+                value: "aéz".to_owned(),
+                cursor: 2,
+            }
+        );
+
+        assert_eq!(
+            paste("aéz", 2, 2, "🦀"),
+            Edit {
+                value: "aé🦀z".to_owned(),
+                cursor: 3,
+            }
+        );
+    }
+
+    #[test]
+    fn locked_menu_allows_copy_and_select_all_only() {
+        assert!(!menu_action_enabled(
+            MenuAction::Cut,
+            true,
+            true,
+            false,
+            true
+        ));
+        assert!(menu_action_enabled(
+            MenuAction::Copy,
+            true,
+            true,
+            false,
+            true
+        ));
+        assert!(!menu_action_enabled(
+            MenuAction::Paste,
+            true,
+            true,
+            false,
+            true
+        ));
+        assert!(menu_action_enabled(
+            MenuAction::SelectAll,
+            true,
+            true,
+            false,
+            true
+        ));
+
+        assert!(!menu_action_enabled(
+            MenuAction::Copy,
+            false,
+            true,
+            false,
+            true
+        ));
+        assert!(!menu_action_enabled(
+            MenuAction::SelectAll,
+            false,
+            false,
+            false,
+            true
+        ));
+    }
+}
@@ -0,0 +1,2 @@
+pub mod context_input;
+pub mod selectable_text;
@@ -0,0 +1,820 @@
+use iced::advanced::clipboard::{self, Clipboard};
+use iced::advanced::layout;
+use iced::advanced::mouse;
+use iced::advanced::renderer;
+use iced::advanced::text::{self as advanced_text, Paragraph, Span};
+use iced::advanced::widget::Widget;
+use iced::advanced::widget::tree::{self, Tree};
+use iced::advanced::{Layout, Shell};
+use iced::widget::text::{
+    self as widget_text, Alignment, Catalog, LineHeight, Shaping, Style, StyleFn, Wrapping,
+};
+use iced::{
+    Background, Border, Color, Element, Event, Length, Pixels, Point, Rectangle, Size, Vector,
+    alignment, keyboard,
+};
+
+const DRAG_THRESHOLD: f32 = 3.0;
+const HIT_SEARCH_STEPS: usize = 24;
+
+// Offsets here are paragraph-global BYTE offsets. `Paragraph::hit_test` returns
+// `Hit::CharOffset(cursor.index)`, and cosmic-text's `cursor.index` is a byte
+// offset WITHIN its buffer line — it discards the line number. That equals the
+// global byte offset only when the text is a single logical line. Chat bodies
+// satisfy this because `app::sanitize_chat` turns every control char (incl. `\n`
+// and `\r`) into a space and collapses whitespace, so a stored message can never
+// contain a newline. If that sanitizer ever starts preserving newlines, this
+// widget's per-line offsets would stop being global and selection/copy across
+// lines would break — revisit then.
+
+pub fn selected_substring(text: &str, anchor: usize, cursor: usize) -> Option<String> {
+    let (start, end) = normalized_byte_range(text, anchor, cursor);
+
+    (start != end).then(|| text[start..end].to_owned())
+}
+
+pub fn select_all(text: &str) -> (usize, usize) {
+    (0, text.len())
+}
+
+fn normalized_byte_range(text: &str, anchor: usize, cursor: usize) -> (usize, usize) {
+    let start = clamp_to_char_boundary(text, anchor.min(cursor));
+    let end = clamp_to_char_boundary(text, anchor.max(cursor));
+
+    (start.min(end), start.max(end))
+}
+
+fn clamp_to_char_boundary(text: &str, offset: usize) -> usize {
+    let mut offset = offset.min(text.len());
+
+    while offset > 0 && !text.is_char_boundary(offset) {
+        offset -= 1;
+    }
+
+    offset
+}
+
+pub fn selectable_rich_text<'a, Link, Message, Theme, Renderer>(
+    spans: impl AsRef<[Span<'a, Link, Renderer::Font>]> + 'a,
+) -> SelectableRichText<'a, Link, Message, Theme, Renderer>
+where
+    Link: Clone + 'static,
+    Theme: Catalog + 'a,
+    Renderer: advanced_text::Renderer,
+    Renderer::Font: 'a,
+{
+    SelectableRichText::with_spans(spans)
+}
+
+pub struct SelectableRichText<'a, Link, Message, Theme = iced::Theme, Renderer = iced::Renderer>
+where
+    Link: Clone + 'static,
+    Theme: Catalog,
+    Renderer: advanced_text::Renderer,
+{
+    spans: Box<dyn AsRef<[Span<'a, Link, Renderer::Font>]> + 'a>,
+    size: Option<Pixels>,
+    line_height: LineHeight,
+    width: Length,
+    height: Length,
+    font: Option<Renderer::Font>,
+    align_x: Alignment,
+    align_y: alignment::Vertical,
+    wrapping: Wrapping,
+    class: Theme::Class<'a>,
+    hovered_link: Option<usize>,
+    on_link_click: Option<Box<dyn Fn(Link) -> Message + 'a>>,
+    selection_color: Color,
+}
+
+impl<'a, Link, Message, Theme, Renderer> SelectableRichText<'a, Link, Message, Theme, Renderer>
+where
+    Link: Clone + 'static,
+    Theme: Catalog,
+    Renderer: advanced_text::Renderer,
+    Renderer::Font: 'a,
+{
+    pub fn new() -> Self {
+        Self {
+            spans: Box::new([]),
+            size: None,
+            line_height: LineHeight::default(),
+            width: Length::Shrink,
+            height: Length::Shrink,
+            font: None,
+            align_x: Alignment::Default,
+            align_y: alignment::Vertical::Top,
+            wrapping: Wrapping::default(),
+            class: Theme::default(),
+            hovered_link: None,
+            on_link_click: None,
+            selection_color: Color::from_rgba(0.35, 0.55, 0.95, 0.35),
+        }
+    }
+
+    pub fn with_spans(spans: impl AsRef<[Span<'a, Link, Renderer::Font>]> + 'a) -> Self {
+        Self {
+            spans: Box::new(spans),
+            ..Self::new()
+        }
+    }
+
+    pub fn size(mut self, size: impl Into<Pixels>) -> Self {
+        self.size = Some(size.into());
+        self
+    }
+
+    pub fn line_height(mut self, line_height: impl Into<LineHeight>) -> Self {
+        self.line_height = line_height.into();
+        self
+    }
+
+    pub fn font(mut self, font: impl Into<Renderer::Font>) -> Self {
+        self.font = Some(font.into());
+        self
+    }
+
+    pub fn width(mut self, width: impl Into<Length>) -> Self {
+        self.width = width.into();
+        self
+    }
+
+    pub fn height(mut self, height: impl Into<Length>) -> Self {
+        self.height = height.into();
+        self
+    }
+
+    pub fn align_x(mut self, alignment: impl Into<Alignment>) -> Self {
+        self.align_x = alignment.into();
+        self
+    }
+
+    pub fn align_y(mut self, alignment: impl Into<alignment::Vertical>) -> Self {
+        self.align_y = alignment.into();
+        self
+    }
+
+    pub fn wrapping(mut self, wrapping: Wrapping) -> Self {
+        self.wrapping = wrapping;
+        self
+    }
+
+    pub fn on_link_click(mut self, on_link_click: impl Fn(Link) -> Message + 'a) -> Self {
+        self.on_link_click = Some(Box::new(on_link_click));
+        self
+    }
+
+    pub fn selection_color(mut self, color: Color) -> Self {
+        self.selection_color = Color {
+            a: color.a.min(0.35),
+            ..color
+        };
+        self
+    }
+
+    pub fn style(mut self, style: impl Fn(&Theme) -> Style + 'a) -> Self
+    where
+        Theme::Class<'a>: From<StyleFn<'a, Theme>>,
+    {
+        self.class = (Box::new(style) as StyleFn<'a, Theme>).into();
+        self
+    }
+
+    pub fn color(self, color: impl Into<Color>) -> Self
+    where
+        Theme::Class<'a>: From<StyleFn<'a, Theme>>,
+    {
+        self.color_maybe(Some(color))
+    }
+
+    pub fn color_maybe(self, color: Option<impl Into<Color>>) -> Self
+    where
+        Theme::Class<'a>: From<StyleFn<'a, Theme>>,
+    {
+        let color = color.map(Into::into);
+
+        self.style(move |_theme| Style { color })
+    }
+
+    pub fn class(mut self, class: impl Into<Theme::Class<'a>>) -> Self {
+        self.class = class.into();
+        self
+    }
+}
+
+impl<'a, Link, Message, Theme, Renderer> Default
+    for SelectableRichText<'a, Link, Message, Theme, Renderer>
+where
+    Link: Clone + 'static,
+    Theme: Catalog,
+    Renderer: advanced_text::Renderer,
+    Renderer::Font: 'a,
+{
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+struct SelectableTextState<Link, P: Paragraph> {
+    spans: Vec<Span<'static, Link, P::Font>>,
+    span_pressed: Option<usize>,
+    paragraph: P,
+    selection: Option<(usize, usize)>,
+    dragging: bool,
+    active: bool,
+    press_position: Option<Point>,
+}
+
+impl<Link, P: Paragraph> SelectableTextState<Link, P> {
+    fn selection_range(&self, text: &str) -> Option<(usize, usize)> {
+        let (anchor, cursor) = self.selection?;
+        let (start, end) = normalized_byte_range(text, anchor, cursor);
+
+        (start != end).then_some((start, end))
+    }
+}
+
+impl<Link, Message, Theme, Renderer> Widget<Message, Theme, Renderer>
+    for SelectableRichText<'_, Link, Message, Theme, Renderer>
+where
+    Link: Clone + 'static,
+    Theme: Catalog,
+    Renderer: advanced_text::Renderer,
+{
+    fn tag(&self) -> tree::Tag {
+        tree::Tag::of::<SelectableTextState<Link, Renderer::Paragraph>>()
+    }
+
+    fn state(&self) -> tree::State {
+        tree::State::new(SelectableTextState::<Link, _> {
+            spans: Vec::new(),
+            span_pressed: None,
+            paragraph: Renderer::Paragraph::default(),
+            selection: None,
+            dragging: false,
+            active: false,
+            press_position: None,
+        })
+    }
+
+    fn size(&self) -> Size<Length> {
+        Size {
+            width: self.width,
+            height: self.height,
+        }
+    }
+
+    fn layout(
+        &mut self,
+        tree: &mut Tree,
+        renderer: &Renderer,
+        limits: &layout::Limits,
+    ) -> layout::Node {
+        layout_text(
+            tree.state
+                .downcast_mut::<SelectableTextState<Link, Renderer::Paragraph>>(),
+            renderer,
+            limits,
+            TextLayout {
+                width: self.width,
+                height: self.height,
+                spans: self.spans.as_ref().as_ref(),
+                line_height: self.line_height,
+                size: self.size,
+                font: self.font,
+                align_x: self.align_x,
+                align_y: self.align_y,
+                wrapping: self.wrapping,
+            },
+        )
+    }
+
+    fn draw(
+        &self,
+        tree: &Tree,
+        renderer: &mut Renderer,
+        theme: &Theme,
+        defaults: &renderer::Style,
+        layout: Layout<'_>,
+        _cursor: mouse::Cursor,
+        viewport: &Rectangle,
+    ) {
+        if !layout.bounds().intersects(viewport) {
+            return;
+        }
+
+        let state = tree
+            .state
+            .downcast_ref::<SelectableTextState<Link, Renderer::Paragraph>>();
+        let spans = self.spans.as_ref().as_ref();
+        let flat_text = flatten_spans(spans);
+        let style = theme.style(&self.class);
+        let translation = layout.position() - Point::ORIGIN;
+
+        if let Some((start, end)) = state.selection_range(&flat_text) {
+            let mut rects = selection_rects(&state.paragraph, spans.len(), start, end);
+            if rects.is_empty() {
+                rects = visual_lines(&state.paragraph, spans.len());
+            }
+
+            for bounds in rects {
+                renderer.fill_quad(
+                    renderer::Quad {
+                        bounds: bounds + translation,
+                        border: Border {
+                            radius: 2.0.into(),
+                            ..Border::default()
+                        },
+                        ..renderer::Quad::default()
+                    },
+                    Background::Color(self.selection_color),
+                );
+            }
+        }
+
+        for (index, span) in spans.iter().enumerate() {
+            let is_hovered_link = self.on_link_click.is_some() && Some(index) == self.hovered_link;
+
+            if span.highlight.is_some() || span.underline || span.strikethrough || is_hovered_link {
+                let regions = state.paragraph.span_bounds(index);
+
+                if let Some(highlight) = span.highlight {
+                    for bounds in &regions {
+                        let bounds = Rectangle::new(
+                            bounds.position() - Vector::new(span.padding.left, span.padding.top),
+                            bounds.size() + Size::new(span.padding.x(), span.padding.y()),
+                        );
+
+                        renderer.fill_quad(
+                            renderer::Quad {
+                                bounds: bounds + translation,
+                                border: highlight.border,
+                                ..Default::default()
+                            },
+                            highlight.background,
+                        );
+                    }
+                }
+
+                if span.underline || span.strikethrough || is_hovered_link {
+                    let size = span.size.or(self.size).unwrap_or(renderer.default_size());
+
+                    let line_height = span
+                        .line_height
+                        .unwrap_or(self.line_height)
+                        .to_absolute(size);
+
+                    let color = span.color.or(style.color).unwrap_or(defaults.text_color);
+
+                    let baseline =
+                        translation + Vector::new(0.0, size.0 + (line_height.0 - size.0) / 2.0);
+
+                    if span.underline || is_hovered_link {
+                        for bounds in &regions {
+                            renderer.fill_quad(
+                                renderer::Quad {
+                                    bounds: Rectangle::new(
+                                        bounds.position() + baseline
+                                            - Vector::new(0.0, size.0 * 0.08),
+                                        Size::new(bounds.width, 1.0),
+                                    ),
+                                    ..Default::default()
+                                },
+                                color,
+                            );
+                        }
+                    }
+
+                    if span.strikethrough {
+                        for bounds in &regions {
+                            renderer.fill_quad(
+                                renderer::Quad {
+                                    bounds: Rectangle::new(
+                                        bounds.position() + baseline
+                                            - Vector::new(0.0, size.0 / 2.0),
+                                        Size::new(bounds.width, 1.0),
+                                    ),
+                                    ..Default::default()
+                                },
+                                color,
+                            );
+                        }
+                    }
+                }
+            }
+        }
+
+        widget_text::draw(
+            renderer,
+            defaults,
+            layout.bounds(),
+            &state.paragraph,
+            style,
+            viewport,
+        );
+    }
+
+    fn update(
+        &mut self,
+        tree: &mut Tree,
+        event: &Event,
+        layout: Layout<'_>,
+        cursor: mouse::Cursor,
+        _renderer: &Renderer,
+        clipboard: &mut dyn Clipboard,
+        shell: &mut Shell<'_, Message>,
+        _viewport: &Rectangle,
+    ) {
+        let bounds = layout.bounds();
+        let local_position = cursor.position_in(bounds);
+        let state = tree
+            .state
+            .downcast_mut::<SelectableTextState<Link, Renderer::Paragraph>>();
+        let spans = self.spans.as_ref().as_ref();
+        let flat_text = flatten_spans(spans);
+
+        let was_hovered = self.hovered_link.is_some();
+        self.hovered_link = local_position.and_then(|position| {
+            state.paragraph.hit_span(position).and_then(|span| {
+                if spans.get(span)?.link.is_some() {
+                    Some(span)
+                } else {
+                    None
+                }
+            })
+        });
+
+        if was_hovered != self.hovered_link.is_some() {
+            shell.request_redraw();
+        }
+
+        match event {
+            Event::Mouse(mouse::Event::ButtonPressed(mouse::Button::Left)) => {
+                if let Some(position) = local_position {
+                    state.active = true;
+                    state.dragging = true;
+                    state.press_position = Some(position);
+                    state.span_pressed = self.hovered_link;
+                    state.selection = state.paragraph.hit_test(position).map(|hit| {
+                        let offset = hit.cursor().min(flat_text.len());
+                        (offset, offset)
+                    });
+                    shell.capture_event();
+                    shell.request_redraw();
+                } else if state.active || state.selection.is_some() {
+                    state.active = false;
+                    state.dragging = false;
+                    state.press_position = None;
+                    state.span_pressed = None;
+                    state.selection = None;
+                    shell.request_redraw();
+                }
+            }
+            Event::Mouse(mouse::Event::CursorMoved { .. }) => {
+                if state.dragging
+                    && let Some(position) = clamped_position(cursor, bounds)
+                    && let Some(hit) = state.paragraph.hit_test(position)
+                    && let Some((anchor, _)) = state.selection
+                {
+                    state.selection = Some((anchor, hit.cursor().min(flat_text.len())));
+                    shell.request_redraw();
+                }
+            }
+            Event::Mouse(mouse::Event::ButtonReleased(mouse::Button::Left)) => {
+                if state.dragging {
+                    let release_position = clamped_position(cursor, bounds)
+                        .or(local_position)
+                        .or(state.press_position);
+                    let dragged = state
+                        .press_position
+                        .zip(release_position)
+                        .is_some_and(|(start, end)| point_distance(start, end) > DRAG_THRESHOLD);
+
+                    if let Some(position) = release_position
+                        && let Some(hit) = state.paragraph.hit_test(position)
+                        && let Some((anchor, _)) = state.selection
+                    {
+                        state.selection = Some((anchor, hit.cursor().min(flat_text.len())));
+                    }
+
+                    if !dragged {
+                        if let (Some(on_link_clicked), Some(span)) =
+                            (&self.on_link_click, state.span_pressed)
+                            && Some(span) == self.hovered_link
+                            && let Some(link) = spans.get(span).and_then(|span| span.link.clone())
+                        {
+                            shell.publish(on_link_clicked(link));
+                        }
+                        state.selection = None;
+                    } else if state.selection_range(&flat_text).is_none() {
+                        state.selection = None;
+                    }
+
+                    state.dragging = false;
+                    state.span_pressed = None;
+                    state.press_position = None;
+                    shell.capture_event();
+                    shell.request_redraw();
+                }
+            }
+            Event::Keyboard(keyboard::Event::KeyPressed {
+                key,
+                physical_key,
+                modifiers,
+                ..
+            }) if state.active && modifiers.command() => match key.to_latin(*physical_key) {
+                Some('c') | Some('C') => {
+                    if let Some((anchor, cursor)) = state.selection
+                        && let Some(selected) = selected_substring(&flat_text, anchor, cursor)
+                    {
+                        clipboard.write(clipboard::Kind::Standard, selected);
+                        shell.capture_event();
+                    }
+                }
+                Some('a') | Some('A') => {
+                    state.selection = Some(select_all(&flat_text));
+                    shell.capture_event();
+                    shell.request_redraw();
+                }
+                _ => {}
+            },
+            _ => {}
+        }
+    }
+
+    fn mouse_interaction(
+        &self,
+        tree: &Tree,
+        layout: Layout<'_>,
+        cursor: mouse::Cursor,
+        _viewport: &Rectangle,
+        _renderer: &Renderer,
+    ) -> mouse::Interaction {
+        let state = tree
+            .state
+            .downcast_ref::<SelectableTextState<Link, Renderer::Paragraph>>();
+
+        if state.dragging {
+            mouse::Interaction::Text
+        } else if self.hovered_link.is_some() {
+            mouse::Interaction::Pointer
+        } else if cursor.is_over(layout.bounds()) {
+            mouse::Interaction::Text
+        } else {
+            mouse::Interaction::None
+        }
+    }
+}
+
+struct TextLayout<'a, 'span, Link, Font> {
+    width: Length,
+    height: Length,
+    spans: &'a [Span<'span, Link, Font>],
+    line_height: LineHeight,
+    size: Option<Pixels>,
+    font: Option<Font>,
+    align_x: Alignment,
+    align_y: alignment::Vertical,
+    wrapping: Wrapping,
+}
+
+fn layout_text<Link, Renderer>(
+    state: &mut SelectableTextState<Link, Renderer::Paragraph>,
+    renderer: &Renderer,
+    limits: &layout::Limits,
+    config: TextLayout<'_, '_, Link, Renderer::Font>,
+) -> layout::Node
+where
+    Link: Clone,
+    Renderer: advanced_text::Renderer,
+{
+    layout::sized(limits, config.width, config.height, |limits| {
+        let bounds = limits.max();
+        let size = config.size.unwrap_or_else(|| renderer.default_size());
+        let font = config.font.unwrap_or_else(|| renderer.default_font());
+
+        let text_with_spans = || advanced_text::Text {
+            content: config.spans,
+            bounds,
+            size,
+            line_height: config.line_height,
+            font,
+            align_x: config.align_x,
+            align_y: config.align_y,
+            shaping: Shaping::Advanced,
+            wrapping: config.wrapping,
+        };
+
+        if state.spans != config.spans {
+            state.paragraph = Renderer::Paragraph::with_spans(text_with_spans());
+            state.spans = config.spans.iter().cloned().map(Span::to_static).collect();
+        } else {
+            match state.paragraph.compare(advanced_text::Text {
+                content: (),
+                bounds,
+                size,
+                line_height: config.line_height,
+                font,
+                align_x: config.align_x,
+                align_y: config.align_y,
+                shaping: Shaping::Advanced,
+                wrapping: config.wrapping,
+            }) {
+                advanced_text::Difference::None => {}
+                advanced_text::Difference::Bounds => {
+                    state.paragraph.resize(bounds);
+                }
+                advanced_text::Difference::Shape => {
+                    state.paragraph = Renderer::Paragraph::with_spans(text_with_spans());
+                }
+            }
+        }
+
+        state.paragraph.min_bounds()
+    })
+}
+
+fn flatten_spans<Link, Font>(spans: &[Span<'_, Link, Font>]) -> String {
+    spans
+        .iter()
+        .map(|span| span.text.as_ref())
+        .collect::<String>()
+}
+
+fn selection_rects<P: Paragraph>(
+    paragraph: &P,
+    span_count: usize,
+    start: usize,
+    end: usize,
+) -> Vec<Rectangle> {
+    visual_lines(paragraph, span_count)
+        .into_iter()
+        .filter_map(|line| selection_rect_for_line(paragraph, line, start, end))
+        .collect()
+}
+
+fn selection_rect_for_line<P: Paragraph>(
+    paragraph: &P,
+    line: Rectangle,
+    start: usize,
+    end: usize,
+) -> Option<Rectangle> {
+    let y = line.center_y();
+    let paragraph_width = paragraph.bounds().width.max(line.x + line.width + 1.0);
+    let left_probe = line.x.max(0.0);
+    let right_probe = (line.x + line.width + 1.0).min(paragraph_width.max(1.0));
+    let line_start = paragraph
+        .hit_test(Point::new(left_probe, y))
+        .map(advanced_text::Hit::cursor)?;
+    let line_end = paragraph
+        .hit_test(Point::new(right_probe, y))
+        .map(advanced_text::Hit::cursor)
+        .unwrap_or(line_start);
+    let (line_start, line_end) = if line_start <= line_end {
+        (line_start, line_end)
+    } else {
+        (line_end, line_start)
+    };
+    let overlap_start = start.max(line_start);
+    let overlap_end = end.min(line_end);
+
+    if overlap_start >= overlap_end {
+        return None;
+    }
+
+    let x_start = if overlap_start <= line_start {
+        line.x
+    } else {
+        x_for_offset(paragraph, y, overlap_start, line.x, line.x + line.width)
+    };
+    let x_end = if overlap_end >= line_end {
+        line.x + line.width
+    } else {
+        x_for_offset(paragraph, y, overlap_end, line.x, line.x + line.width)
+    };
+    let left = x_start.min(x_end);
+    let right = x_start.max(x_end);
+
+    (right > left).then(|| {
+        Rectangle::new(
+            Point::new(left, line.y),
+            Size::new(right - left, line.height),
+        )
+    })
+}
+
+fn x_for_offset<P: Paragraph>(paragraph: &P, y: f32, offset: usize, left: f32, right: f32) -> f32 {
+    let mut low = left;
+    let mut high = right.max(left);
+
+    for _ in 0..HIT_SEARCH_STEPS {
+        let mid = (low + high) / 2.0;
+        let hit = paragraph
+            .hit_test(Point::new(mid, y))
+            .map(advanced_text::Hit::cursor);
+
+        match hit {
+            Some(hit) if hit < offset => low = mid,
+            Some(_) => high = mid,
+            None => break,
+        }
+    }
+
+    high
+}
+
+fn visual_lines<P: Paragraph>(paragraph: &P, span_count: usize) -> Vec<Rectangle> {
+    let mut lines: Vec<Rectangle> = Vec::new();
+
+    for span in 0..span_count {
+        for bounds in paragraph.span_bounds(span) {
+            if bounds.width <= 0.0 || bounds.height <= 0.0 {
+                continue;
+            }
+
+            if let Some(line) = lines
+                .iter_mut()
+                .find(|line| (line.center_y() - bounds.center_y()).abs() < 1.0)
+            {
+                *line = union(*line, bounds);
+            } else {
+                lines.push(bounds);
+            }
+        }
+    }
+
+    lines.sort_by(|a, b| a.y.total_cmp(&b.y));
+    lines
+}
+
+fn union(a: Rectangle, b: Rectangle) -> Rectangle {
+    let left = a.x.min(b.x);
+    let top = a.y.min(b.y);
+    let right = (a.x + a.width).max(b.x + b.width);
+    let bottom = (a.y + a.height).max(b.y + b.height);
+
+    Rectangle::new(Point::new(left, top), Size::new(right - left, bottom - top))
+}
+
+fn clamped_position(cursor: mouse::Cursor, bounds: Rectangle) -> Option<Point> {
+    cursor.position_from(bounds.position()).map(|position| {
+        Point::new(
+            position.x.clamp(0.0, bounds.width.max(1.0) - 1.0),
+            position.y.clamp(0.0, bounds.height.max(1.0) - 1.0),
+        )
+    })
+}
+
+fn point_distance(a: Point, b: Point) -> f32 {
+    let dx = a.x - b.x;
+    let dy = a.y - b.y;
+
+    (dx * dx + dy * dy).sqrt()
+}
+
+impl<'a, Link, Message, Theme, Renderer>
+    From<SelectableRichText<'a, Link, Message, Theme, Renderer>>
+    for Element<'a, Message, Theme, Renderer>
+where
+    Message: 'a,
+    Link: Clone + 'a,
+    Theme: Catalog + 'a,
+    Renderer: advanced_text::Renderer + 'a,
+{
+    fn from(
+        text: SelectableRichText<'a, Link, Message, Theme, Renderer>,
+    ) -> Element<'a, Message, Theme, Renderer> {
+        Element::new(text)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn selected_substring_returns_middle_and_none_for_collapsed() {
+        assert_eq!(selected_substring("abcdef", 2, 5), Some("cde".to_owned()));
+        assert_eq!(selected_substring("abcdef", 3, 3), None);
+    }
+
+    #[test]
+    fn selected_substring_handles_reversed_range() {
+        assert_eq!(selected_substring("abcdef", 5, 2), Some("cde".to_owned()));
+    }
+
+    #[test]
+    fn select_all_uses_byte_length() {
+        assert_eq!(select_all(""), (0, 0));
+        assert_eq!(select_all("aé👍z"), (0, "aé👍z".len()));
+    }
+
+    #[test]
+    fn unicode_selection_uses_byte_offsets_without_panicking() {
+        let text = "aé👍z";
+
+        assert_eq!(selected_substring(text, 1, 7), Some("é👍".to_owned()));
+        assert_eq!(selected_substring(text, 3, 7), Some("👍".to_owned()));
+        assert_eq!(selected_substring(text, 2, 7), Some("é👍".to_owned()));
+    }
+}
@@ -21,7 +21,7 @@ use iroh::endpoint::presets;
 use iroh::protocol::Router;
 use iroh::{Endpoint, RelayMode};

-use peerspeak::files::{ChatAttachment, AttachmentKind};
+use peerspeak::files::{AttachmentKind, ChatAttachment};
 use peerspeak::network::NetworkTransport;
 use peerspeak::network::iroh_impl::{FileRouter, IrohTransport};
 use peerspeak::protocol::FILES_ALPN;
@@ -52,7 +52,12 @@ async fn spawn_node() -> Node {
        .accept(FILES_ALPN, file_router)
        .spawn();

-    Node { endpoint, transport, _router: router, lookup }
+    Node {
+        endpoint,
+        transport,
+        _router: router,
+        lookup,
+    }
 }

 /// A pseudo-random-ish multi-megabyte payload spanning many QUIC packets, so a
@@ -86,7 +91,9 @@ async fn loopback_attachment_round_trips_intact() {

    let blob = big_blob();
    let id = [42u8; 32];
-    server.transport.serve_attachment(id, Arc::new(blob.clone()));
+    server
+        .transport
+        .serve_attachment(id, Arc::new(blob.clone()));

    let att = ChatAttachment {
        name: "exterior-landscape.jpg".to_string(),
@@ -64,6 +64,7 @@ fn state(name: &str, addr: EndpointAddr) -> PeerState {
        sharing: None,
        avatar: Default::default(),
        game: None,
+        music: None,
    }
 }

@@ -62,7 +62,7 @@ async fn evicted_within(
            Ok(Some(UiEvent::PeerConnectionFailed { id })) if id == peer => return true,
            Ok(Some(_)) => continue, // ignore PeerConnecting / PeerConnected / PeerLeft
            Ok(None) => return false, // channel closed
-            Err(_) => return false,   // timed out — no eviction
+            Err(_) => return false,  // timed out — no eviction
        }
    }
 }
@@ -80,7 +80,7 @@ async fn left_within(
            Ok(Some(UiEvent::PeerLeft { id })) if id == peer => return true,
            Ok(Some(_)) => continue, // ignore PeerConnecting / PeerConnected
            Ok(None) => return false, // channel closed
-            Err(_) => return false,   // timed out — no leave
+            Err(_) => return false,  // timed out — no leave
        }
    }
 }
@@ -23,8 +23,8 @@ use iroh::protocol::{AcceptError, ProtocolHandler};
 use peerspeak::codec::AudioEncoder;
 use peerspeak::codec::opus_impl::OpusEncoder;
 use peerspeak::core::jitter::{FRAME_SAMPLES, JitterBuffer};
-use peerspeak::network::{ConnEvent, NetworkTransport};
 use peerspeak::network::iroh_impl::{AudioRouter, IrohTransport};
+use peerspeak::network::{ConnEvent, NetworkTransport};
 use peerspeak::protocol::AUDIO_ALPN;

 struct Node {
@@ -91,7 +91,12 @@ async fn spawn_capture_peer(secret: iroh::SecretKey) -> CapturePeer {
        .accept(AUDIO_ALPN, CaptureProtocol { conns_tx })
        .spawn();

-    CapturePeer { endpoint, _router: router, lookup, conns_rx }
+    CapturePeer {
+        endpoint,
+        _router: router,
+        lookup,
+        conns_rx,
+    }
 }

 /// Spawn a node with a specific secret key. Reusing a key gives the respawned
@@ -208,7 +213,11 @@ async fn loopback_sequenced_audio_reaches_peer_and_decodes() {
        received += 1;

        if let Some(frame) = jitter.pop_frame() {
-            assert_eq!(frame.len(), FRAME_SAMPLES, "decoded frame is one 20ms frame");
+            assert_eq!(
+                frame.len(),
+                FRAME_SAMPLES,
+                "decoded frame is one 20ms frame"
+            );
            decoded_frames += 1;
        }
        if received >= N {
@@ -235,6 +244,71 @@ async fn loopback_sequenced_audio_reaches_peer_and_decodes() {
    );
 }

+/// Connection transparency: over a real loopback link, `connection_stats()`
+/// must report the peer's selected path as direct (relay disabled here), with
+/// an IP remote address and counters that advance while audio flows — and the
+/// `connstats::derive` seam must turn two such snapshots into badge info with
+/// live rates.
+#[tokio::test]
+async fn connection_stats_report_a_direct_path_with_live_counters() {
+    let a = spawn_node().await;
+    let b = spawn_node().await;
+
+    a.lookup.add_endpoint_info(b.endpoint.addr());
+    b.lookup.add_endpoint_info(a.endpoint.addr());
+
+    let a_id = a.endpoint.id();
+    let b_id = b.endpoint.id();
+    a.transport.admit_audio_sender(b_id);
+    b.transport.admit_audio_sender(a_id);
+
+    // Keep B's receive path subscribed like production (drained implicitly).
+    let _b_rx = b.transport.receive_datagrams().await.expect("subscribe B");
+
+    a.transport.connect_peer(b.endpoint.addr()).await;
+    b.transport.connect_peer(a.endpoint.addr()).await;
+    tokio::time::sleep(Duration::from_millis(500)).await;
+
+    let snap = |stats: Vec<(iroh::EndpointId, peerspeak::network::PathSnapshot)>| {
+        stats
+            .into_iter()
+            .find(|(id, _)| *id == b_id)
+            .map(|(_, s)| s)
+            .expect("peer B should appear in A's connection stats")
+    };
+    let s1 = snap(a.transport.connection_stats());
+    assert!(!s1.is_relay, "loopback with relay disabled must be direct");
+    assert!(
+        s1.remote_addr.parse::<std::net::SocketAddr>().is_ok(),
+        "direct path address should be ip:port, got {}",
+        s1.remote_addr
+    );
+
+    // Stream real audio so the path counters move.
+    let mut enc = OpusEncoder::new(48000, Channels::Mono, Application::Voip).unwrap();
+    for seq in 0..25u32 {
+        a.transport.broadcast(packet(&mut enc, seq));
+        tokio::time::sleep(Duration::from_millis(5)).await;
+    }
+
+    let s2 = snap(a.transport.connection_stats());
+    assert!(s2.tx_bytes > s1.tx_bytes, "sent bytes should advance");
+    assert!(
+        s2.tx_datagrams > s1.tx_datagrams,
+        "sent datagrams should advance"
+    );
+
+    // The derivation seam turns the two snapshots into live badge info.
+    let info = peerspeak::core::connstats::derive(Some(&s1), &s2, Duration::from_millis(200));
+    assert!(!info.relay);
+    assert_eq!(info.remote_addr, s2.remote_addr);
+    assert!(info.rtt_ms < 1000, "localhost RTT should be sane");
+    assert!(
+        info.up_kbps.expect("same path + positive window has a rate") > 0.0,
+        "audio was flowing, so the upstream rate must be non-zero"
+    );
+}
+
 /// Read datagrams off a raw connection until `target` arrive or the deadline
 /// passes, asserting each carries the 4-byte sequence header.
 async fn count_audio(conn: &Connection, target: u32, deadline: tokio::time::Instant) -> u32 {
@@ -290,7 +364,11 @@ async fn dialer_reconnects_after_link_drops() {
        .expect("timed out awaiting initial connection")
        .expect("connection channel closed");
    assert!(
-        await_reconnect(&mut conn_events, tokio::time::Instant::now() + Duration::from_secs(10)).await,
+        await_reconnect(
+            &mut conn_events,
+            tokio::time::Instant::now() + Duration::from_secs(10)
+        )
+        .await,
        "initial link should report Connecting then Connected"
    );

@@ -306,7 +384,11 @@ async fn dialer_reconnects_after_link_drops() {
        .expect("timed out awaiting reconnect")
        .expect("connection channel closed");
    assert!(
-        await_reconnect(&mut conn_events, tokio::time::Instant::now() + Duration::from_secs(15)).await,
+        await_reconnect(
+            &mut conn_events,
+            tokio::time::Instant::now() + Duration::from_secs(15)
+        )
+        .await,
        "dropped link should report Connecting (down) then Connected (recovered)"
    );

@@ -319,7 +401,12 @@ async fn dialer_reconnects_after_link_drops() {
        tokio::time::sleep(Duration::from_millis(5)).await;
    }

-    let received = count_audio(&conn2, 25, tokio::time::Instant::now() + Duration::from_secs(3)).await;
+    let received = count_audio(
+        &conn2,
+        25,
+        tokio::time::Instant::now() + Duration::from_secs(3),
+    )
+    .await;
    assert!(
        received >= 20,
        "audio should resume after reconnect; got {received} frames"
@@ -359,7 +446,11 @@ async fn dialer_reports_left_on_graceful_close() {
        .expect("timed out awaiting initial connection")
        .expect("connection channel closed");
    assert!(
-        await_reconnect(&mut conn_events, tokio::time::Instant::now() + Duration::from_secs(10)).await,
+        await_reconnect(
+            &mut conn_events,
+            tokio::time::Instant::now() + Duration::from_secs(10)
+        )
+        .await,
        "initial link should report Connecting then Connected"
    );

@@ -384,7 +475,10 @@ async fn dialer_reports_left_on_graceful_close() {

    // And no re-dial reaches the peer within a short window.
    let redial = tokio::time::timeout(Duration::from_secs(2), peer.conns_rx.recv()).await;
-    assert!(redial.is_err(), "supervisor must not re-dial after a graceful leave");
+    assert!(
+        redial.is_err(),
+        "supervisor must not re-dial after a graceful leave"
+    );
 }

 #[tokio::test]
@@ -429,7 +523,11 @@ async fn dialer_connects_and_reconnects_without_an_address_lookup() {
        .expect("timed out awaiting initial connection (retained address path)")
        .expect("connection channel closed");
    assert!(
-        await_reconnect(&mut conn_events, tokio::time::Instant::now() + Duration::from_secs(10)).await,
+        await_reconnect(
+            &mut conn_events,
+            tokio::time::Instant::now() + Duration::from_secs(10)
+        )
+        .await,
        "initial link should report Connecting then Connected"
    );

@@ -443,7 +541,11 @@ async fn dialer_connects_and_reconnects_without_an_address_lookup() {
        .expect("timed out awaiting reconnect (retained address path)")
        .expect("connection channel closed");
    assert!(
-        await_reconnect(&mut conn_events, tokio::time::Instant::now() + Duration::from_secs(15)).await,
+        await_reconnect(
+            &mut conn_events,
+            tokio::time::Instant::now() + Duration::from_secs(15)
+        )
+        .await,
        "reconnect should report Connecting then Connected with no lookup at all"
    );

@@ -455,7 +557,12 @@ async fn dialer_connects_and_reconnects_without_an_address_lookup() {
        tokio::time::sleep(Duration::from_millis(5)).await;
    }

-    let received = count_audio(&conn2, 25, tokio::time::Instant::now() + Duration::from_secs(3)).await;
+    let received = count_audio(
+        &conn2,
+        25,
+        tokio::time::Instant::now() + Duration::from_secs(3),
+    )
+    .await;
    assert!(
        received >= 20,
        "audio should resume after reconnecting via the retained address; got {received} frames"