Mirrors flutter_client/lib/cache/db.dart's AudioCacheIndex — one row
per fully-downloaded audio file. Drives the 2-bucket LRU eviction
policy that Phase 12's AudioCacheEvictionWorker will execute.
DAO surface tailored to the eviction worker:
- totalBytes / bytesBySource — sum-of-sizeBytes for cap checks
- evictionCandidates(source) — oldest lastPlayedAt within a source
bucket, NULL lastPlayedAt sorted first (never-played candidates
evict before played ones)
- touchLastPlayed(trackId, instant) — single-column update from
the player on every "ready+playing" transition
- bulk delete by track-id list for batch evictions
CacheSource enum (MANUAL / INCIDENTAL / AUTO_PREFETCH) ported in
Task 4.1's TypeConverters.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
bvandeusen
e63034ec9c