Fix deepcopy the chat model (#17560)

api/db/services/llm_service.py

@@ -86,6 +86,18 @@ class LLMBundle(LLM4Tenant):
         """Release resources held by this LLMBundle instance."""
         super().close()
 
+    def clone(self):
+        kwargs = {
+            "trace_context": dict(self.trace_context or {}),
+            "langfuse_session_id": self.langfuse_session_id,
+            "verbose_tool_use": self.verbose_tool_use,
+        }
+        for attr, key in (("max_retries", "max_retries"), ("base_delay", "retry_interval"), ("max_rounds", "max_rounds")):
+            value = getattr(self.mdl, attr, None)
+            if value is not None:
+                kwargs[key] = value
+        return LLMBundle(self.tenant_id, dict(self.model_config), lang=getattr(self, "lang", "Chinese"), **kwargs)
+
     def __enter__(self):
         """Enter context manager."""
         return self

api/db/services/tenant_llm_service.py

@@ -508,6 +508,7 @@ class LLM4Tenant:
         self.trace_context = kwargs.pop("trace_context", None) or {}
         self.langfuse_session_id = kwargs.pop("langfuse_session_id", None)
         self.tenant_id = tenant_id
+        self.lang = lang
         self.llm_name = model_config["llm_name"]
         self.model_config = model_config
         self.mdl = TenantLLMService.model_instance(model_config, lang=lang, **kwargs)