Three failures from the prior push:
1. internal/api/library.go and 3 other callers of q.GetArtistByID
broke because T2 modified the query to use an explicit column
list, making sqlc generate GetArtistByIDRow instead of returning
dbq.Artist. dbq.Artist already has every column added by
migration 0018 (artist_thumb_path / artist_fanart_path /
artist_art_source / artist_art_sources_version), so the explicit
column list was unnecessary work. Revert the SELECT to SELECT *,
regenerate sqlc, GetArtistByIDRow disappears, all callers compile
again.
2. internal/tracks/service_test.go missed the dataDir parameter
added to NewService in T9. Add "" as the 4th arg to every test
call site (tests don't exercise the artist-art cleanup path; the
empty dataDir is fine).
3. integrations.test.ts:356's mock.calls.filter callback had a
too-narrow type annotation that svelte-check rejected. Relax to
any[] to match what mock.calls actually is.