errors

mnemo_cards_backend/lib/api/mnemo_shelf.dart

@@ -83,10 +83,18 @@ class MnemoShelf {
 
           // Process the request and add CORS headers to response
           final response = await innerHandler(request);
-          return response.change(headers: {
-            ...response.headers,
-            ...corsConfig,
+          
+          // Explicitly merge headers to ensure CORS headers are always added
+          // This guarantees CORS headers are present even for error responses (401, 403, etc.)
+          final finalHeaders = <String, String>{};
+          // First, add existing response headers
+          finalHeaders.addAll(response.headers);
+          // Then, add/override with CORS headers (they take priority)
+          corsConfig.forEach((key, value) {
+            finalHeaders[key] = value;
           });
+          
+          return response.change(headers: finalHeaders);
         };
       };
     }