- Column accessor shows '0' instead of empty string for unplayed tracks
- recordPlay emits TrackMetadataChanged event after updating DB
- Frontend library store invalidates on that event, refreshing play counts
Migration 10:
- play_history table (audio_file_id FK, played_at DATETIME, CASCADE delete)
- play_count + last_played columns on audio_files (denormalized)
- Recreated track_metadata VIEW with play_count and last_played columns
Play recording:
- queue.recordPlay() inserts play_history row + updates denormalized columns
- Called from OnPlaybackFinished after queue advance completes
- Mutex released before DB write to avoid MaxOpenConns(1) deadlock
- Natural finish only — skip/stop does not count
Tests:
- TestMigration10PlayHistory: schema, columns, VIEW, round-trip verification
- All 49 smart playlist + 15 service + existing DB tests still pass