fix: fallback to index+1 for Deezer track position when API returns 0

go_backend/deezer.go

@@ -340,10 +340,16 @@ func (c *DeezerClient) GetAlbum(ctx context.Context, albumID string) (*AlbumResp
 		albumType = "compilation"
 	}
 
-	for _, track := range album.Tracks.Data {
+	for i, track := range album.Tracks.Data {
 		trackIDStr := fmt.Sprintf("%d", track.ID)
 		isrc := isrcMap[trackIDStr]
 
+		// Use track position from API, fallback to index+1 if not provided
+		trackNum := track.TrackPosition
+		if trackNum == 0 {
+			trackNum = i + 1
+		}
+
 		tracks = append(tracks, AlbumTrackMetadata{
 			SpotifyID:   fmt.Sprintf("deezer:%d", track.ID),
 			Artists:     track.Artist.Name,
@@ -353,7 +359,7 @@ func (c *DeezerClient) GetAlbum(ctx context.Context, albumID string) (*AlbumResp
 			DurationMS:  track.Duration * 1000,
 			Images:      albumImage,
 			ReleaseDate: album.ReleaseDate,
-			TrackNumber: track.TrackPosition,
+			TrackNumber: trackNum,
 			TotalTracks: album.NbTracks,
 			DiscNumber:  track.DiskNumber,
 			ExternalURL: track.Link,