Update OpenRouter_Agent.py

OpenRouter_Agent.py

@@ -129,4 +129,9 @@ class MultiAgentSystem:
             raise Exception(output)
         return True
 
-
+    def __call__(self, task: str) -> str:
+        """
+        Run the manager_agent on the given user task and
+        return its final answer text.
+        """
+        return self.manager_agent(task)