Update LangGraphAgent to use glm-4.5-air model instead of deepseek-r1-0528

agent.py

@@ -78,7 +78,7 @@ class LangGraphAgent:
             #     model="gemma-3-27b-it",
             # )
             model = ChatOpenRouter(
-                model="deepseek/deepseek-r1-0528:free",
+                model="z-ai/glm-4.5-air:free",
                 temperature=0.1,
             )
             if model is None and ChatOpenAI is not None: