fix(subsonic): expose cover cache-buster on bookmarked songs

GetBookmarks selected media_file.* without the album cover-stamp projection,
so bookmarked songs kept emitting the pre-edit coverArt id after a cover
upload/delete. With this fourth copy of the projection appearing, extract it
into a shared coverArtUpdatedAtCol helper used by all media_file read paths
(list, playlist tracks, single playlist track, bookmarks).

persistence/helpers.go

@@ -90,3 +90,9 @@ func mapSortOrder(tableName, order string) string {
 	repl := fmt.Sprintf("(coalesce(nullif(%[1]s.sort_$1,''),%[1]s.order_$1) collate nocase)", tableName)
 	return sortOrderRegex.ReplaceAllString(order, repl)
 }
+
+// coverArtUpdatedAtCol projects the album's manual-cover timestamp onto rows of the given
+// table/alias as a scalar subquery — a join would clash with media_file's column names.
+func coverArtUpdatedAtCol(alias string) string {
+	return "(select cover_art_updated_at from album where album.id = " + alias + ".album_id) as cover_art_updated_at"
+}

persistence/mediafile_repository.go

@@ -184,10 +184,8 @@ func (r *mediaFileRepository) UpdateProbeData(id string, data string) error {
 }
 
 func (r *mediaFileRepository) selectMediaFile(options ...model.QueryOptions) SelectBuilder {
-	// Scalar subquery (not a join): album shares column names with media_file, and a join
-	// would make unqualified filter/sort references ambiguous.
 	sql := r.newSelect(options...).Columns("media_file.*", "library.path as library_path", "library.name as library_name",
-		"(select cover_art_updated_at from album where album.id = media_file.album_id) as cover_art_updated_at").
+		coverArtUpdatedAtCol("media_file")).
 		LeftJoin("library on media_file.library_id = library.id")
 	sql = r.withAnnotation(sql, "media_file.id")
 	sql = r.withBookmark(sql, "media_file.id")

persistence/playlist_repository.go

@@ -314,7 +314,7 @@ func (r *playlistRepository) tracksQuery(query SelectBuilder, id string) SelectB
 			"playlist_tracks.*",
 			"library.path as library_path",
 			"library.name as library_name",
-			"(select cover_art_updated_at from album where album.id = f.album_id) as cover_art_updated_at",
+			coverArtUpdatedAtCol("f"),
 		).
 		LeftJoin("annotation on (" +
 			"annotation.item_id = media_file_id" +

persistence/playlist_track_repository.go

@@ -108,7 +108,7 @@ func (r *playlistTrackRepository) Read(id string) (any, error) {
 			"rated_at",
 			"f.*",
 			"playlist_tracks.*",
-			"(select cover_art_updated_at from album where album.id = f.album_id) as cover_art_updated_at",
+			coverArtUpdatedAtCol("f"),
 		).
 		Join("media_file f on f.id = media_file_id").
 		Where(And{Eq{"playlist_id": r.playlistId}, Eq{"playlist_tracks.id": id}})

persistence/sql_bookmarks.go

@@ -100,7 +100,9 @@ func (r sqlRepository) GetBookmarks() (model.Bookmarks, error) {
 	user, _ := request.UserFrom(r.ctx)
 
 	idField := r.tableName + ".id"
-	sq := r.newSelect().Columns(r.tableName + ".*")
+	// Only media files are bookmarkable (see dbMediaFiles scan below), so the cover
+	// stamp projection is safe to add here
+	sq := r.newSelect().Columns(r.tableName+".*", coverArtUpdatedAtCol(r.tableName))
 	sq = r.withAnnotation(sq, idField)
 	sq = r.withBookmark(sq, idField).Where(NotEq{bookmarkTable + ".item_id": nil})
 	var mfs dbMediaFiles // TODO Decouple from media_file

persistence/sql_bookmarks_test.go

@@ -3,6 +3,7 @@ package persistence
 import (
 	"context"
 
+	"github.com/Masterminds/squirrel"
 	"github.com/navidrome/navidrome/log"
 	"github.com/navidrome/navidrome/model"
 	"github.com/navidrome/navidrome/model/request"
@@ -70,5 +71,24 @@ var _ = Describe("sqlBookmarks", func() {
 			Expect(mr.DeleteBookmark(songComeTogether.ID)).To(Succeed())
 			Expect(mr.GetBookmarks()).To(BeEmpty())
 		})
+
+		It("exposes the album's cover timestamp on bookmarked songs", func() {
+			albumRepo := NewAlbumRepository(request.WithUser(GinkgoT().Context(), model.User{ID: "userid"}), GetDBXBuilder()).(*albumRepository)
+			Expect(mr.AddBookmark(songAntenna.ID, "cover test", 1)).To(Succeed())
+			DeferCleanup(func() {
+				_ = mr.DeleteBookmark(songAntenna.ID)
+				// Restore both columns so fixture-equality tests stay untouched
+				_, _ = albumRepo.executeSQL(squirrel.Update("album").
+					Set("uploaded_image", "").Set("cover_art_updated_at", nil).
+					Where(squirrel.Eq{"id": songAntenna.AlbumID}))
+			})
+
+			Expect(albumRepo.UpdateImage(songAntenna.AlbumID, "cover-bm.jpg")).To(Succeed())
+
+			bms, err := mr.GetBookmarks()
+			Expect(err).ToNot(HaveOccurred())
+			Expect(bms).To(HaveLen(1))
+			Expect(bms[0].Item.CoverArtUpdatedAt).ToNot(BeNil())
+		})
 	})
 })