fix: Clone a new agent per session to isolate the session conversation from others

Gradio_UI.py

@@ -184,7 +184,7 @@ class AgentCloner:
         self.agent = agent
         self.model_client = agent.model
 
-    def clone():
+    def clone(self):
         new_model_client = HfApiModel(
             max_tokens=self.model.max_tokens,
             temperature=self.model.temperature,