Update chat_router.py

backend/api/chat_router.py

@@ -119,7 +119,7 @@ async def chat_completion(
         f"knowledge_graph_id: {request.knowledge_graph_id}, "
         f"llm_provider: {request.llm_provider}, llm_model: {request.llm_model}, ip={client_ip}"
     )
-    request.llm_model = "qwen3-max"
+    request.llm_model = "qwen3.7-plus"
     request.llm_provider = "tongyi"
     # ============ 内容审核前置处理 ============
     # 在 AI 处理前对用户消息进行内容审核