docs(06-02): complete audio feature extraction and segment overlay plan

- Create 06-02-SUMMARY.md with full execution record
- Update STATE.md: plan advanced to 3/3, progress 95%, decisions logged
- Update ROADMAP.md: phase 6 now 2/3 summaries
- Mark SYNC-03 complete in REQUIREMENTS.md

.planning/ROADMAP.md

@@ -127,7 +127,7 @@ Plans:
 
 Plans:
 - [x] 06-01: YouTube loading — yt-dlp download to /app/shows/, SSE progress streaming, transport bar URL input
-- [ ] 06-02: Feature extraction + segmentation — onset/chroma/RMS extraction, structural segmentation API, colored section band overlay on waveform
+- [x] 06-02: Feature extraction + segmentation — onset/chroma/RMS extraction, structural segmentation API, colored section band overlay on waveform
 - [ ] 06-03: AI sync engine — heuristic block mapper + optional LLM generation, AI Sync panel UI, per-section fill
 
 ### Phase 7: Microcontroller Firmware
@@ -158,5 +158,5 @@ Phases execute in numeric order: 1 → 2 → 3 → 4 → 5 → 6 → 7
 | 3. Communication Protocol | 3/3 | Complete   | 2026-04-06 |
 | 4. Timeline Editor | 4/4 | Complete   | 2026-04-06 |
 | 5. Live Show Execution | 4/4 | Complete   | 2026-04-07 |
-| 6. AI Sync | 1/3 | In Progress|  |
+| 6. AI Sync | 2/3 | In Progress|  |
 | 7. Microcontroller Firmware | 0/3 | Not started | - |