feat: fetch all artist albums with caching, filter by type in handler

- Provider fetches all release groups via paginated browse, no type filter
- Service caches all albums in DB, ensures referenced artists exist first
- Server handler filters by album_types (default: album|ep|single), excludes secondary types
- Add secondary_types to domain, DB schema, and MB types
- Add ErrBadRequest handling for MusicBrainz 400 errors
- Replace migrations with single schema.sql
- Add GetAllByArtistID and SaveAll to album repository

internal/provider/musicbrainz/mapper.go

@@ -61,9 +61,10 @@ func mapAlbum(mb *mbReleaseGroup, release *mbRelease) *domain.Album {
 	}
 
 	album := &domain.Album{
-		ID:    mb.ID,
-		Title: mb.Title,
-		Type:  mb.PrimaryType,
+		ID:             mb.ID,
+		Title:          mb.Title,
+		Type:           mb.PrimaryType,
+		SecondaryTypes: mb.SecondaryTypes,
 		ExternalIDs: []domain.ExternalID{{
 			Source:   "musicbrainz",
 			SourceID: mb.ID,