apply security audit

backend/src/middleware/error.middleware.ts

@@ -46,9 +46,7 @@ export const errorHandler = (
 
   res.status(500).json({
     status: 'error',
-    message: process.env.NODE_ENV === 'production'
-      ? 'Internal server error'
-      : err.message,
+    message: 'An internal error occurred',
   });
 };