feat(35): scenes remember the room — BRB mutes the mic on entry

591 green, 0 warnings.

- `Scene.SceneMutesMic` / `SceneMutesDesktop` are **nullable booleans**: null = leave the mix alone, so
  a scene is passive until the creator says otherwise. Schema columns added, NULL for every existing
  layout except one deliberate default.
- **Applied once when the scene takes the PROGRAM output** (`TransitionToScene`, only when live or
  recording). Staging a scene offline is auditioning, not a stream edit — the test asserts that.
- **The creator is boss:** a manual mute survives any transition into a scene with no opinion; a scene
  that does have one wins on its next entry. `SetMicMuted`/`SetGameMuted` are idempotent so a repeated
  "mute" cannot clobber the level that unmute would restore.
- **BRB ships muted** (creator spec) for new layouts *and* via a one-time migration for existing rows
  where the creator has never expressed an opinion.
- UI: two three-state checkboxes under the layers list ("When this scene goes live"), styled with
  `PropertyPillCheck` so the theme test holds.

`SceneAudioTests` covers the whole rule in one integration test: default state, offline staging does
nothing, live entry mutes, manual unmute survives a passive scene, an opinionated scene wins, desktop
untouched, and all three states roundtrip through save/reload.

Needs the creator's eye: the checkboxes are new chrome in the left panel (indeterminate = passive).

TASKS.md

@@ -9,7 +9,7 @@
 
 **Creator ruling 2026-11-09 — finish the queue before the new features, gold pass always last.**
 
-`35 → 37 → 40·A/C/D → 55·2–3 → Move → 9·5 → 14 (slices) → 65 → 66 → 67 → 68 → 36`
+`37 → 40·A/C/D → 55·2–3 → Move → 9·5 → 14 (slices) → 65 → 66 → 67 → 68 → 36`
 
 The rule behind the two retirements below: **do not rebuild the platform's own surface.** Scheduling,
 publishing, moderation and channel management are YouTube's; the app owns capture → scene → sound →
@@ -19,7 +19,7 @@ output.
 
 | Task | Status | Scope | Detail |
 |---|---|---|---|
-| 35 | ☐ | **Scene-linked audio** — the scene remembers the room: BRB mutes the mic, Chat restores it, applied once at the live transition | [`task-35`](TASKS/task-35-scene-linked-audio.md) |
+| 35 | ✅ | **Scene-linked audio** — the scene remembers the room: BRB ships muted, three-state checkboxes per scene, applied once when the scene takes the program output (done 2026-11-10) | [`task-35`](TASKS/task-35-scene-linked-audio.md) |
 | 37 | ☐ | **Defaults vs current layout split** — separate branded defaults from the live workspace; enables one-click revert | [`task-37`](TASKS/task-37-defaults-current-split.md) |
 | 40·A/C/D | ☐ | **Settings round** — active-camera picker; persist output resolution + surface transition defaults + confirm-before-End; accent consolidation | [`task-40`](TASKS/task-40-app-settings-round.md) |
 | 55·2–3 | ☐ | **Disk hygiene** — delete `%TEMP%` alert clips on close + sweep at startup; low-disk guard before REC (slice 1 shipped) | [`task-55`](TASKS/task-55-disk-hygiene.md) |