fix: correct track/disc defaults, forward extension metadata, and fix service ID display

- Default track/disc number to 0 (unknown) instead of 1, letting the
  backend use the service-provided value or skip the field entirely
- Add releaseDate to ExploreItem so explore downloads carry release info
- Pass discNumber and releaseDate from extension album/playlist tracks
- Fix isDeezer detection using service field instead of substring match
- Add _displayServiceTrackId() to properly strip prefixes for all services

lib/providers/download_queue_provider.dart

@@ -2811,8 +2811,8 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
         'artist': track.artistName,
         'album': track.albumName,
         'album_artist': resolvedAlbumArtist,
-        'track_number': track.trackNumber ?? 1,
-        'disc_number': track.discNumber ?? 1,
+        'track_number': track.trackNumber ?? 0,
+        'disc_number': track.discNumber ?? 0,
         'isrc': track.isrc ?? '',
         'release_date': track.releaseDate ?? '',
         'duration_ms': track.duration * 1000,
@@ -4649,12 +4649,12 @@ class DownloadQueueNotifier extends Notifier<DownloadQueueState> {
             (trackToDownload.trackNumber != null &&
                 trackToDownload.trackNumber! > 0)
             ? trackToDownload.trackNumber!
-            : 1;
+            : 0;
         final normalizedDiscNumber =
             (trackToDownload.discNumber != null &&
                 trackToDownload.discNumber! > 0)
             ? trackToDownload.discNumber!
-            : 1;
+            : 0;
 
         String payloadSpotifyId = trackToDownload.id;
         String payloadQobuzId = '';

lib/providers/explore_provider.dart

@@ -19,6 +19,7 @@ class ExploreItem {
   final String? providerId;
   final String? albumId;
   final String? albumName;
+  final String? releaseDate;
   final int durationMs;
 
   const ExploreItem({
@@ -32,6 +33,7 @@ class ExploreItem {
     this.providerId,
     this.albumId,
     this.albumName,
+    this.releaseDate,
     this.durationMs = 0,
   });
 
@@ -47,6 +49,7 @@ class ExploreItem {
       providerId: json['provider_id'] as String?,
       albumId: json['album_id'] as String?,
       albumName: json['album_name'] as String?,
+      releaseDate: json['release_date']?.toString(),
       durationMs: json['duration_ms'] as int? ?? 0,
     );
   }
@@ -62,6 +65,7 @@ class ExploreItem {
     'provider_id': providerId,
     'album_id': albumId,
     'album_name': albumName,
+    'release_date': releaseDate,
     'duration_ms': durationMs,
   };
 }