Add internal API method and fix playlist count authentication

- Added GetJsonAsyncInternal method to JellyfinProxyService for server-side requests
- Uses server API key instead of client tokens for internal operations
- Updated UpdateSpotifyPlaylistCounts to use internal method with proper authentication
- This should resolve 401 Unauthorized errors when updating playlist counts

Now Spotify playlists should show correct track counts without authentication issues.

allstarr/Controllers/JellyfinController.cs

@@ -2823,15 +2823,15 @@ public class JellyfinController : ControllerBase
                                     // Include UserId parameter to avoid 401 Unauthorized
                                     var userId = _settings.UserId;
                                     var playlistItemsUrl = $"Playlists/{playlistId}/Items";
+                                    var queryParams = new Dictionary<string, string>();
                                     if (!string.IsNullOrEmpty(userId))
                                     {
-                                        playlistItemsUrl += $"?UserId={userId}";
+                                        queryParams["UserId"] = userId;
                                     }
                                     
-                                    var (localTracksResponse, _) = await _proxyService.GetJsonAsync(
+                                    var (localTracksResponse, _) = await _proxyService.GetJsonAsyncInternal(
                                         playlistItemsUrl, 
-                                        null, 
-                                        Request.Headers);
+                                        queryParams);
                                     
                                     if (localTracksResponse != null && 
                                         localTracksResponse.RootElement.TryGetProperty("Items", out var localItems))

allstarr/Services/Jellyfin/JellyfinProxyService.cs

@@ -967,4 +967,43 @@ public class JellyfinProxyService
 
         return url;
     }
+
+    /// <summary>
+    /// Sends a GET request to the Jellyfin server using the server's API key for internal operations.
+    /// This should only be used for server-side operations, not for proxying client requests.
+    /// </summary>
+    public async Task<(JsonDocument? Body, int StatusCode)> GetJsonAsyncInternal(string endpoint, Dictionary<string, string>? queryParams = null)
+    {
+        var url = BuildUrl(endpoint, queryParams);
+        
+        using var request = new HttpRequestMessage(HttpMethod.Get, url);
+        
+        // Use server's API key for authentication
+        var authHeader = GetAuthorizationHeader();
+        request.Headers.TryAddWithoutValidation("X-Emby-Authorization", authHeader);
+        
+        request.Headers.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
+
+        var response = await _httpClient.SendAsync(request);
+        var statusCode = (int)response.StatusCode;
+        var content = await response.Content.ReadAsStringAsync();
+        
+        if (!response.IsSuccessStatusCode)
+        {
+            _logger.LogWarning("Jellyfin internal request returned {StatusCode} for {Url}: {Content}", 
+                statusCode, url, content);
+            return (null, statusCode);
+        }
+
+        try
+        {
+            var jsonDocument = JsonDocument.Parse(content);
+            return (jsonDocument, statusCode);
+        }
+        catch (JsonException ex)
+        {
+            _logger.LogError(ex, "Failed to parse JSON response from {Url}: {Content}", url, content);
+            return (null, statusCode);
+        }
+    }
 }