fix: include full track metadata in GetAudioFilesByReleaseGroup query

The GetAudioFilesByReleaseGroup SQL query only selected 6 columns,
missing audio properties (sample_rate, bit_depth, channels, bitrate,
file_size) and metadata (album, genre, year, composer, file_type).
This caused track details opened from the album view to show dashes
instead of actual values. Expanded the query to match
GetAllTracksWithFullMetadata and updated GetAlbumTracks to use the
shared mapTrackRow helper.

backend/library/query.go

@@ -217,17 +217,24 @@ func (l *Library) GetAlbumTracks(albumID int64) ([]Track, error) {
 	tracks := make([]Track, 0, len(rows))
 
 	for _, row := range rows {
-		tracks = append(tracks, Track{
-			TrackName:  row.Title,
-			ArtistName: row.ArtistName,
-			TrackLength: strconv.FormatInt(
-				row.LengthMilliseconds,
-				10,
-			),
-			FilePath:    row.FilePath,
-			TrackNumber: row.TrackNumber.Int64,
-			DiscNumber:  row.DiscNumber.Int64,
-		})
+		tracks = append(tracks, mapTrackRow(
+			row.FilePath,
+			row.LengthMilliseconds,
+			row.Title,
+			row.ArtistName,
+			row.TrackNumber,
+			row.DiscNumber,
+			row.Album,
+			row.Genre,
+			row.Year,
+			row.Composer,
+			row.FileType,
+			row.SampleRate,
+			row.BitDepth,
+			row.Channels,
+			row.Bitrate,
+			row.FileSize,
+		))
 	}
 
 	return tracks, nil