Fix Spotify playlist injection: add dedicated route, startup fetch, and clarify config

allstarr/Controllers/JellyfinController.cs

@@ -1210,6 +1210,17 @@ public class JellyfinController : ControllerBase
 
     #region Playlists
 
+    /// <summary>
+    /// Intercepts playlist items requests to inject Spotify playlists.
+    /// This route must have lower Order than the catch-all ProxyRequest route.
+    /// </summary>
+    [HttpGet("Playlists/{playlistId}/Items", Order = 5)]
+    public async Task<IActionResult> GetPlaylistItems(string playlistId)
+    {
+        _logger.LogInformation("GetPlaylistItems called for playlist {PlaylistId}", playlistId);
+        return await GetPlaylistTracks(playlistId);
+    }
+
     /// <summary>
     /// Gets playlist tracks displayed as an album.
     /// </summary>