chore: senior-review cleanup pass

- Remove Gemini's committed update_*.py regex-surgery scripts
- Drop unused iroh-tickets dependency (hand-rolled ticket is used instead)
- Replace ToString antipattern with Display impl on PeerSpeakTicket
- Route debug log to XDG state/cache dir instead of hardcoded /home path
- Clear all compiler + clippy warnings (unused imports, collapsible ifs,
  redundant pattern matching, missing Default)

Builds clean with zero warnings.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Cargo.lock

@@ -324,15 +324,6 @@ dependencies = [
  "rustc_version",
 ]
 
-[[package]]
-name = "atomic-polyfill"
-version = "1.0.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8cf2bce30dfe09ef0bfaef228b9d414faaf7e563035494d7fe092dba54b300f4"
-dependencies = [
- "critical-section",
-]
-
 [[package]]
 name = "atomic-waker"
 version = "1.1.2"
@@ -529,12 +520,6 @@ dependencies = [
  "syn",
 ]
 
-[[package]]
-name = "byteorder"
-version = "1.5.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1fd0f2584146f6f2ef48085050886acf353beff7305ebd1ae69500e27c67f64b"
-
 [[package]]
 name = "bytes"
 version = "1.11.1"
@@ -1601,7 +1586,7 @@ dependencies = [
  "diatomic-waker",
  "futures-core",
  "pin-project-lite",
- "spin 0.10.0",
+ "spin",
 ]
 
 [[package]]
@@ -1950,15 +1935,6 @@ dependencies = [
  "smallvec",
 ]
 
-[[package]]
-name = "hash32"
-version = "0.2.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b0c35f58762feb77d74ebe43bdbc3210f09be9fe6742234d573bacc26ed92b67"
-dependencies = [
- "byteorder",
-]
-
 [[package]]
 name = "hashbrown"
 version = "0.15.5"
@@ -1988,20 +1964,6 @@ dependencies = [
  "foldhash 0.2.0",
 ]
 
-[[package]]
-name = "heapless"
-version = "0.7.17"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cdc6457c0eb62c71aac4bc17216026d8410337c4126773b9c5daba343f17964f"
-dependencies = [
- "atomic-polyfill",
- "hash32",
- "rustc_version",
- "serde",
- "spin 0.9.8",
- "stable_deref_trait",
-]
-
 [[package]]
 name = "heck"
 version = "0.5.0"
@@ -2812,20 +2774,6 @@ dependencies = [
  "ws_stream_wasm",
 ]
 
-[[package]]
-name = "iroh-tickets"
-version = "1.0.0-rc.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0a4b7fbfa10582f6b4f6b013eef1d21987d3df5fd42c0f7707d5de6abd34f8e9"
-dependencies = [
- "data-encoding",
- "derive_more",
- "iroh-base",
- "n0-error",
- "postcard",
- "serde",
-]
-
 [[package]]
 name = "irpc"
 version = "0.15.0"
@@ -4180,7 +4128,6 @@ dependencies = [
  "iced",
  "iroh",
  "iroh-gossip",
- "iroh-tickets",
  "opus",
  "pipewire",
  "rand",
@@ -4405,7 +4352,6 @@ dependencies = [
  "cobs",
  "embedded-io 0.4.0",
  "embedded-io 0.6.1",
- "heapless",
  "postcard-derive",
  "serde",
 ]
@@ -5284,15 +5230,6 @@ dependencies = [
  "syn",
 ]
 
-[[package]]
-name = "spin"
-version = "0.9.8"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6980e8d7511241f8acf4aebddbb1ff938df5eebe98691418c4468d0b72a96a67"
-dependencies = [
- "lock_api",
-]
-
 [[package]]
 name = "spin"
 version = "0.10.0"