Before album tracks start post-processing, pre-populate the MusicBrainz
release cache with ONE verified release. All tracks then hit the cache
during per-track processing and get the same release MBID — no second pass,
no file lock contention, tags correct on first write.
Handles edition name mismatches (Spotify says 'Super Deluxe', MB says
just the base name) by stripping qualifiers and searching again.
Validates track count to pick the right edition. Three download paths
covered: download missing modal, enhanced album, and matched album.
