- New split layout: waveform/transport/queue left, comment panel right
- Avatar pins above waveform positioned by timestamp with hover tooltips
- Transport bar: speed selector, ±30s skip, 46px amber play/pause, volume
- Comment compose: live timestamp pill, suggestion/issue/keeper tag buttons
- Comment list: per-author colour avatars, amber timestamp seek chips,
playhead-proximity highlight, delete only shown on own comments
- Queue panel showing other songs in the same session
- Waveform colours updated to amber/dim palette (104px height)
- Add GET /songs/{song_id} endpoint for song metadata
- Add tag field to SongComment (model, schema, router, migration 0005)
- Fix migration 0005 down_revision to use short ID "0004"
- Fix ESLint no-unused-expressions in keyboard shortcut handler
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Introduces the rehearsal session concept: each YYMMDD folder in
Nextcloud maps to one RehearsalSession row (band_id + date unique).
Songs gain a nullable session_id FK and a tags TEXT[] column for
manual labeling (searchable by name, tag, BPM, key).
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>