Fix lyrics fetching and disable prefetching

- Fix LyricsPrefetchService to use server API key for Jellyfin lyrics checks
- Remove Spotify lyrics caching (local Docker container is fast)
- Disable lyrics prefetching service (not needed - Jellyfin/Spotify are fast)
- Add POST /api/admin/cache/clear-lyrics endpoint to clear LRCLIB cache
- Only LRCLIB lyrics are cached now (external API)

allstarr/Controllers/AdminController.cs

@@ -1738,6 +1738,30 @@ public class AdminController : ControllerBase
         });
     }
     
+    /// <summary>
+    /// Clear all cached lyrics (LRCLIB only - Jellyfin and Spotify lyrics are not cached)
+    /// </summary>
+    [HttpPost("cache/clear-lyrics")]
+    public async Task<IActionResult> ClearLyricsCache()
+    {
+        _logger.LogInformation("Lyrics cache clear requested from admin UI");
+        
+        var clearedRedisKeys = 0;
+        
+        // Clear all lyrics cache keys (pattern-based deletion)
+        // This includes LRCLIB lyrics and manual mappings
+        var lyricsKeysDeleted = await _cache.DeleteByPatternAsync("lyrics:*");
+        clearedRedisKeys += lyricsKeysDeleted;
+        
+        _logger.LogInformation("Lyrics cache cleared: {RedisKeys} Redis keys deleted", clearedRedisKeys);
+        
+        return Ok(new { 
+            message = "Lyrics cache cleared successfully", 
+            redisKeysDeleted = clearedRedisKeys,
+            note = "Only LRCLIB lyrics are cached. Jellyfin and Spotify lyrics are fetched on-demand (fast)."
+        });
+    }
+    
     /// <summary>
     /// Restart the allstarr container to apply configuration changes
     /// </summary>

allstarr/Program.cs

@@ -568,8 +568,9 @@ builder.Services.AddSingleton<allstarr.Services.Spotify.SpotifyTrackMatchingServ
 builder.Services.AddHostedService(sp => sp.GetRequiredService<allstarr.Services.Spotify.SpotifyTrackMatchingService>());
 
 // Register lyrics prefetch service (prefetches lyrics for all playlist tracks)
-builder.Services.AddSingleton<allstarr.Services.Lyrics.LyricsPrefetchService>();
+// DISABLED - No need to prefetch since Jellyfin and Spotify lyrics are fast
-builder.Services.AddHostedService(sp => sp.GetRequiredService<allstarr.Services.Lyrics.LyricsPrefetchService>());
+// builder.Services.AddSingleton<allstarr.Services.Lyrics.LyricsPrefetchService>();
+// builder.Services.AddHostedService(sp => sp.GetRequiredService<allstarr.Services.Lyrics.LyricsPrefetchService>());
 
 // Register MusicBrainz service for metadata enrichment
 builder.Services.Configure<allstarr.Models.Settings.MusicBrainzSettings>(options =>

allstarr/Services/Lyrics/LyricsPrefetchService.cs

@@ -406,9 +406,9 @@ public class LyricsPrefetchService : BackgroundService
             }
 
             // Directly check if this track has lyrics using the item ID
-            var (lyricsResult, lyricsStatusCode) = await proxyService.GetJsonAsync(
+            // Use internal method with server API key since this is a background operation
+            var (lyricsResult, lyricsStatusCode) = await proxyService.GetJsonAsyncInternal(
                 $"Audio/{jellyfinItemId}/Lyrics", 
-                null, 
                 null);
             
             if (lyricsResult != null && lyricsStatusCode == 200)
@@ -455,7 +455,7 @@ public class LyricsPrefetchService : BackgroundService
                 ["limit"] = "5"  // Get a few results to find best match
             };
 
-            var (searchResult, statusCode) = await proxyService.GetJsonAsync("Items", searchParams, null);
+            var (searchResult, statusCode) = await proxyService.GetJsonAsyncInternal("Items", searchParams);
             
             if (searchResult == null || statusCode != 200)
             {
@@ -511,9 +511,9 @@ public class LyricsPrefetchService : BackgroundService
             }
 
             // Check if this track has lyrics
-            var (lyricsResult, lyricsStatusCode) = await proxyService.GetJsonAsync(
+            // Use internal method with server API key since this is a background operation
+            var (lyricsResult, lyricsStatusCode) = await proxyService.GetJsonAsyncInternal(
                 $"Audio/{bestMatchId}/Lyrics", 
-                null, 
                 null);
             
             if (lyricsResult != null && lyricsStatusCode == 200)

allstarr/Services/Lyrics/SpotifyLyricsService.cs

@@ -63,15 +63,7 @@ public class SpotifyLyricsService
         // Normalize track ID (remove URI prefix if present)
         spotifyTrackId = ExtractTrackId(spotifyTrackId);
         
-        // Check cache
+        // NO CACHING - Spotify lyrics come from local Docker container (fast)
-        var cacheKey = $"spotify:lyrics:{spotifyTrackId}";
-        var cached = await _cache.GetAsync<SpotifyLyricsResult>(cacheKey);
-        if (cached != null)
-        {
-            _logger.LogDebug("Returning cached Spotify lyrics for track {TrackId}", spotifyTrackId);
-            return cached;
-        }
-        
         try
         {
             var url = $"{_settings.LyricsApiUrl}/?trackid={spotifyTrackId}&format=id3";
@@ -92,8 +84,6 @@ public class SpotifyLyricsService
             
             if (result != null)
             {
-                // Cache for 30 days (lyrics don't change)
-                await _cache.SetAsync(cacheKey, result, TimeSpan.FromDays(30));
                 _logger.LogInformation("Got Spotify lyrics from sidecar for track {TrackId} ({LineCount} lines)", 
                     spotifyTrackId, result.Lines.Count);
             }