Issue #442 — MusicBrainz exposes alternate-spelling aliases (Japanese
kanji `澤野弘之` for `Hiroyuki Sawano`, Cyrillic `Сергей Лазарев` for
`Sergey Lazarev`, etc.) on every artist record. SoulSync's MB
enrichment worker had access to this data via `get_artist(mbid,
includes=['aliases'])` but wasn't reading or persisting it.
This commit wires the alias fetch into the worker's existing
artist-match path, persists to the new `artists.aliases` column
added in the prior commit, and adds a verifier-friendly read-by-
name lookup so the AcoustID verifier (next commit) can resolve
aliases without an MB round-trip when the artist is in the library.
# New service methods
- `fetch_artist_aliases(mbid) -> list[str]` — calls
`mb_client.get_artist(mbid, includes=['aliases'])`, parses the
alias array, dedupes case-insensitively. Returns empty list on
any failure (missing key, network error, malformed response) so
transient MB outages never trigger stricter quarantine decisions
than the pre-fix behaviour. Empty mbid → no API call.
- `update_artist_aliases(artist_id, aliases)` — persists as JSON
array to `artists.aliases`. Idempotent — overwrites prior value.
Empty list clears the column. None artist_id is a no-op.
- `get_artist_aliases(artist_name) -> list[str]` — reads back by
artist NAME (not id), case-insensitive. Used by the verifier
where the expected artist comes from track metadata — there's no
library row id at quarantine time. Returns empty list for unknown
artists, missing data, or corrupt JSON (defensive against legacy
rows).
# Worker integration
`MusicBrainzWorker._process_item` artist branch:
- After `update_artist_mbid` succeeds, fetch aliases for the matched
MBID and persist via `update_artist_aliases`.
- Best-effort: alias fetch wrapped in try/except, failure logs at
debug level, doesn't regress the match outcome.
- No alias call when the artist didn't match an MBID (nothing to
enrich).
# Tests (23)
- `fetch_artist_aliases`: extracts names from MB response,
case-insensitive dedup, skips empty/null entries, missing-key
fallback, network failure → empty, empty mbid no API call,
verifies `inc=aliases` request param.
- `update_artist_aliases`: persists as JSON, idempotent overwrite,
empty list clears column, None id is no-op.
- `get_artist_aliases`: returns aliases for known artist,
case-insensitive lookup, empty for unknown artist / no-aliases
row, handles corrupt JSON + non-list shape gracefully.
- Worker integration: matched artist triggers fetch + persist,
no alias call when not matched, alias-fetch failure doesn't
break the match outcome.
# Verification
- 23/23 new tests pass
- Ruff clean
48d848bb74