Add Spotify ID lookup for external tracks to enable Spotify lyrics

- External tracks from playlists now look up their Spotify ID from matched tracks cache
- Enables Spotify lyrics API to work for SquidWTF/Deezer/Qobuz tracks
- Searches through all playlist matched tracks to find the Spotify ID
- Falls back to LRCLIB if no Spotify ID found or lyrics unavailable

allstarr/Controllers/JellyfinController.cs

@@ -1150,7 +1150,18 @@ public class JellyfinController : ControllerBase
         if (isExternal)
         {
             song = await _metadataService.GetSongAsync(provider!, externalId!);
-            // For Deezer tracks, we'll search Spotify by metadata
+            
+            // Try to find Spotify ID from matched tracks cache
+            // External tracks from playlists should have been matched and cached
+            if (song != null)
+            {
+                spotifyTrackId = await FindSpotifyIdForExternalTrackAsync(song);
+                if (!string.IsNullOrEmpty(spotifyTrackId))
+                {
+                    _logger.LogInformation("Found Spotify ID {SpotifyId} for external track {Provider}/{ExternalId}", 
+                        spotifyTrackId, provider, externalId);
+                }
+            }
         }
         else
         {
@@ -4122,5 +4133,51 @@ public class JellyfinController : ControllerBase
         
         return (deviceId, client, device, version);
     }
+    
+    /// <summary>
+    /// Finds the Spotify ID for an external track by searching through all playlist matched tracks caches.
+    /// This allows us to get Spotify lyrics for external tracks that were matched from Spotify playlists.
+    /// </summary>
+    private async Task<string?> FindSpotifyIdForExternalTrackAsync(Song externalSong)
+    {
+        try
+        {
+            // Get all configured playlists
+            var playlists = _spotifySettings.Playlists;
+            
+            // Search through each playlist's matched tracks cache
+            foreach (var playlist in playlists)
+            {
+                var cacheKey = $"spotify:matched:ordered:{playlist.Name}";
+                var matchedTracks = await _cache.GetAsync<List<MatchedTrack>>(cacheKey);
+                
+                if (matchedTracks == null || matchedTracks.Count == 0)
+                    continue;
+                
+                // Look for a match by external ID
+                var match = matchedTracks.FirstOrDefault(t => 
+                    t.MatchedSong != null && 
+                    t.MatchedSong.ExternalProvider == externalSong.ExternalProvider &&
+                    t.MatchedSong.ExternalId == externalSong.ExternalId);
+                
+                if (match != null && !string.IsNullOrEmpty(match.SpotifyId))
+                {
+                    _logger.LogDebug("Found Spotify ID {SpotifyId} for {Provider}/{ExternalId} in playlist {Playlist}", 
+                        match.SpotifyId, externalSong.ExternalProvider, externalSong.ExternalId, playlist.Name);
+                    return match.SpotifyId;
+                }
+            }
+            
+            _logger.LogDebug("No Spotify ID found for external track {Provider}/{ExternalId}", 
+                externalSong.ExternalProvider, externalSong.ExternalId);
+            return null;
+        }
+        catch (Exception ex)
+        {
+            _logger.LogWarning(ex, "Error finding Spotify ID for external track");
+            return null;
+        }
+    }
 }
+
 // force rebuild Sun Jan 25 13:22:47 EST 2026