docs(02-05): complete BeatDetector plan — AUD-03 and AUD-04 fulfilled

- SUMMARY.md: TDD execution documented, deviation noted (module-level time import)
- STATE.md: advanced to plan 3/6, 90% progress, decision logged
- ROADMAP.md: 5/6 summaries complete for phase 02
- REQUIREMENTS.md: AUD-03 and AUD-04 marked complete

.planning/STATE.md

@@ -3,8 +3,8 @@ gsd_state_version: 1.0
 milestone: v1.0
 milestone_name: milestone
 status: executing
-stopped_at: Completed 02-app-core-audio 02-04-PLAN.md
-last_updated: "2026-04-03T12:52:07.259Z"
+stopped_at: Completed 02-app-core-audio 02-05-PLAN.md
+last_updated: "2026-04-03T12:52:14.694Z"
 last_activity: 2026-04-03
 progress:
   total_phases: 4
@@ -95,6 +95,7 @@ Recent decisions affecting current work:
 - [Phase 02-app-core-audio]: Pydantic v2 field_validator + model_post_init pattern established for ChoreoEvent/ChoreoFile models
 - [Phase 02-app-core-audio]: Absolute monotonic timestamps (D-07): fire_at recalculated fresh each 5ms poll — no drift accumulation over any duration
 - [Phase 02-app-core-audio]: pause_offset accumulation (D-09): resume() adds elapsed pause time keeping all fire_at values correct without event skipping
+- [Phase 02-app-core-audio]: D-05 enforced: call_soon_threadsafe bridge pattern in _audio_callback — no direct asyncio calls from audio thread; import time moved to module-level
 
 ### Pending Todos
 
@@ -109,6 +110,6 @@ None yet.
 
 ## Session Continuity
 
-Last session: 2026-04-03T12:51:57.725Z
-Stopped at: Completed 02-app-core-audio 02-04-PLAN.md
+Last session: 2026-04-03T12:52:14.679Z
+Stopped at: Completed 02-app-core-audio 02-05-PLAN.md
 Resume file: None