my-sea voice: persist mute across in-sea nav/refresh + 3-min muted auto-disconnect; fix first-connect glow/mute race — TDD

MUTE PERSISTENCE (user-spec 2026-05-30) — a voice mute used to vanish on any
in-sea navigation/refresh (the mesh tears down + auto-rejoins unmuted). Now the
mute is stamped server-side + re-applied on rejoin, with a 3-min muted →
auto-disconnect window:
- `User.voice_muted_at` (timestamp, not a bare bool, so the 3-min window anchors
  here) + migration. Per-user, not per-seat: the owner has no seat row, and a
  user is in ≤1 voice room at a time, so this uniformly covers owner + visitor.
- POST `/voice/mute` {muted} sets/clears it (new voice app views.py + urls.py,
  mounted at `voice/` in core/urls). my_sea + my_sea_visit pass the timestamp to
  `#id_voice_btn` as `data-voice-muted-at`.
- voice-mesh.js gains `setMuted(m)` (set vs. toggleMute's flip), honoured by
  join's post-getUserMedia `_applyMute`. burger-btn.js: a mute toggle POSTs the
  state + arms a client timer; the auto-rejoin re-applies the persisted mute +
  re-arms the timer from the stored timestamp (so the 3-min spans navigations,
  not resets); an elapsed window on rejoin auto-disconnects instead of rejoining;
  a fresh manual join clears any stale mute. On timeout: leave voice + clear.

FIRST-CONNECT GLOW/MUTE RACE (user-reported) — `setOnStateChange` pushes the
current state immediately on subscribe, and voice-glow.js often subscribes
MID-JOIN (getUserMedia pending → inCall=false). Its `setVoiceState` only ever
DELETED `voice.dataset.inCall` (never re-set it) — wiping the join-vs-mute flag
burger-btn.js had just set, so the next click re-joined instead of muting (which
also dropped the peer + killed the equalizer). Two fixes:
- voice-glow keeps `dataset.inCall` SYMMETRIC (set on true, delete on false), so
  the mid-join false is restored once the stream resolves → mute works on first
  connect.
- voice-glow subscribes reliably on AUTO-REJOIN too (no click to trigger its
  poll): voice-mesh.js dispatches `voiceroom:ready` on singleton creation +
  voice-glow listens, so the glow is mesh-driven (peer-count equalizer) after a
  refresh, not just the in-call-class fallback.

Coverage:
- ITs: VoiceMuteViewTest (login/405/invalid-json guards, stamp on true, clear on
  false, re-mute restamps, missing-key=false). voice+lyric 164 green.
- Jasmine: BurgerSpec mute persistence (muteRemainingMs window, rejoin re-mute,
  expired-window auto-disconnect, toggle-persists + 3-min fires, manual-join
  clears); VoiceGlowSpec dataset.inCall sync (sets on in-call, clears on not,
  restores after a mid-join false→true). All green.
- Live multi-party voice (mic/2-device) left to manual verification.

Code architected by Disco DeDisco <discodedisco@outlook.com>
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/templates/apps/gameboard/_partials/_burger.html

@@ -16,7 +16,10 @@
     {# (owner w. a present invitee, or the present invitee). data-room-id    #}
     {# keys the WebRTC mesh group: mysea-<owner_id>. burger-btn.js binds the #}
     {# active-click → lazy-load voice-mesh.js → join / toggle-mute.          #}
-    <button id="id_voice_btn" type="button" class="burger-fan-btn{% if voice_active %} active{% endif %}" aria-label="Voice"{% if voice_room_id %} data-room-id="{{ voice_room_id }}"{% endif %}>
+    {# data-voice-muted-at carries the persisted mute timestamp so the voice    #}
+    {# auto-rejoin starts MUTED (mute survives in-sea nav/refresh) + anchors the #}
+    {# 3-min muted→auto-disconnect window. Empty/absent = not muted.             #}
+    <button id="id_voice_btn" type="button" class="burger-fan-btn{% if voice_active %} active{% endif %}" aria-label="Voice"{% if voice_room_id %} data-room-id="{{ voice_room_id }}"{% endif %}{% if voice_muted_at %} data-voice-muted-at="{{ voice_muted_at }}"{% endif %}>
         <i class="fa-solid fa-headset burger-fan-icon--on"></i>
         <i class="fa-solid fa-ban burger-fan-icon--off"></i>
     </button>