Fix JSONID type conversions for yandex-music-api-go v0.0.0-20261018072517-d0173f795d2a

The new library version uses models.JSONID (custom string type) for ID
fields instead of plain string. Convert to string where IDs are passed
to functions expecting string or compared with string values.

Affected: client.go (GetTrackInfoWithPosition), downloader.go
(track.ID usage), monitor.go (track.ID, album.ID usage), storage.go
(album/track ID assignment).

internal/downloader/downloader.go

@@ -157,21 +157,21 @@ func (d *Downloader) DownloadAlbum(ctx context.Context, albumID string) []Downlo
 		for i, volume := range album.Volumes {
 			for j := range volume {
 				track := &volume[j]
-				if track.ID == "" || !track.Available {
+				if string(track.ID) == "" || !track.Available {
 					continue
 				}
 
 				// Get download URL (handles XML parsing and URL signing)
-				downloadURL, err := d.yandexClient.GetTrackDownloadURL(ctx, track.ID)
+				downloadURL, err := d.yandexClient.GetTrackDownloadURL(ctx, string(track.ID))
 				if err != nil {
-					results = append(results, DownloadResult{TrackID: track.ID, Success: false, Error: fmt.Errorf("get download URL: %w", err)})
+					results = append(results, DownloadResult{TrackID: string(track.ID), Success: false, Error: fmt.Errorf("get download URL: %w", err)})
 					continue
 				}
 
 				// Get download info for metadata
-				downloadInfos, err := d.yandexClient.GetTrackDownloadInfo(ctx, track.ID)
+				downloadInfos, err := d.yandexClient.GetTrackDownloadInfo(ctx, string(track.ID))
 				if err != nil {
-					results = append(results, DownloadResult{TrackID: track.ID, Success: false, Error: fmt.Errorf("get download info: %w", err)})
+					results = append(results, DownloadResult{TrackID: string(track.ID), Success: false, Error: fmt.Errorf("get download info: %w", err)})
 					continue
 				}
 
@@ -202,19 +202,19 @@ func (d *Downloader) DownloadAlbum(ctx context.Context, albumID string) []Downlo
 				// Download audio
 				audioData, err := d.downloadFile(ctx, downloadURL)
 				if err != nil {
-					results = append(results, DownloadResult{TrackID: track.ID, Success: false, Error: fmt.Errorf("download audio: %w", err)})
+					results = append(results, DownloadResult{TrackID: string(track.ID), Success: false, Error: fmt.Errorf("download audio: %w", err)})
 					continue
 				}
 
 				// Save track
 				if err := d.storage.SaveTrack(trackMeta, audioData, coverData); err != nil {
-					results = append(results, DownloadResult{TrackID: track.ID, Success: false, Error: fmt.Errorf("save track: %w", err)})
+					results = append(results, DownloadResult{TrackID: string(track.ID), Success: false, Error: fmt.Errorf("save track: %w", err)})
 					continue
 				}
 
-				savedMeta, _ := d.storage.GetTrackMeta(track.ID)
+				savedMeta, _ := d.storage.GetTrackMeta(string(track.ID))
 				results = append(results, DownloadResult{
-					TrackID:   track.ID,
+					TrackID:   string(track.ID),
 					AlbumID:   albumID,
 					Success:   true,
 					TrackMeta: savedMeta,