Foundation commit for issue #442 — Japanese kanji ↔ romanized name
quarantines and equivalent cross-script mismatches. MusicBrainz
exposes alternate-spelling aliases on every artist record but
SoulSync's matching never consulted them; cross-script comparison
scored 0% on raw similarity and the file got quarantined even when
MusicBrainz knew both names belonged to the same artist.
This commit only adds the column. Subsequent commits in this PR:
- Build a pure alias-aware artist comparison helper
- Wire the MusicBrainz worker to populate aliases on enrichment
- Add a live MB lookup with cache for un-enriched artists
- Wire the helper into the AcoustID verifier where the quarantine
decision actually fires
Schema change is additive (NULL default), gated by the same
`PRAGMA table_info` check the existing `_add_musicbrainz_columns`
helper uses, so re-running on databases that already have the
column is a no-op.
Verified:
- New `artists.aliases` column present in fresh DB init
- JSON round-trip works (mirrors the existing `genres` column pattern)
- No existing tests broken