Register MusicBrainz as a first-class metadata source alongside Deezer, iTunes, Spotify, Discogs, and Hydrabase. Expose the shared client through metadata services, add the settings option, and expand the MusicBrainz search adapter with source-compatible artist, album, track, and detail methods.
Carry MusicBrainz IDs through similar-artist discovery, recommended artists, artist map serialization, and personalized playlist selection. Update DB migrations and lookup filters so similar_artist_musicbrainz_id is preserved on older schemas and used for source requirements and library exclusion.
Normalize MusicBrainz album adapter output for import context and add regression coverage for registry mapping, typed album conversion, and similar-artist filtering. Verified by user with 120 focused tests passing.
- add neutral wishlist payload helpers while keeping legacy Spotify aliases
- route wishlist removal and classification through generic track data
- keep API and service compatibility for existing callers
