docs: mark W7 P4 transport done (loopback-verified); endpoint fork next

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

docs/contacts-plan.md

@@ -123,12 +123,21 @@ address book), though a lightweight mutual-add is optional polish.
   `PresenceMode` {Invisible, Normal(default), Discoverable} persisted in
   `AppConfig`; `interpret_pong` — defensive (sanitizes peer room name, only
   surfaces a joinable room if the ticket parses, never auto-joins).
-- **Deferred to a 2-machine session (the I/O edges):** bind the live control
-  endpoint on its own ALPN (e.g. `peerspeak/friends/0`) **outside** the room
-  session lifecycle; its accept loop (gated by `should_answer`); the rate-limited
-  outbound ping scheduler (on app open + slow refresh); reporting our current
-  gathering as a member-issued ticket (reuse `restamp`); rendering friend status +
-  a **room-name tag + Join** entry in the friends list (overlaps P5).
+- **Transport DONE 2026-06-15 (`501f76a`):** `src/presence_net.rs` — bind/`probe`/
+  `serve` the ping→pong over ALPN `peerspeak/friends/0`; request/response per conn;
+  `serve` authenticates `remote_id` and asks an injected `Handler` (wraps
+  `should_answer` + builds the pong) what to reply, `None` = reveal nothing to a
+  stranger. **Loopback integration test PASSED over real iroh endpoints** (friend
+  gets Pong+room; stranger gets unusable reply); run with `cargo test -- --ignored
+  presence_net`.
+- **STILL deferred (next session, needs care + 2 machines):**
+  - **The endpoint-lifecycle fork (decide first):** a second always-on endpoint
+    shares our node id with the per-join room endpoint (possible relay/identity
+    collision) vs. refactoring to ONE persistent endpoint that hosts friends +
+    room. Spike/decide before wiring `serve` live.
+  - Spawn `serve` outside the room session; the rate-limited outbound ping
+    scheduler (app open + slow refresh); report our current gathering via
+    `restamp`; render friend status + a **room-name tag + Join** entry (overlaps P5).
 
 ### P5 — Recents + UI — Medium
 Local recents list (cosmetic room tags). Friends-list UI with status dots