Merge pull request #493 from NikoHu1/fix-chapter13-amapExpandable

Fix:修复13章旅行助手代码因为自动扩展字段失效，无法利用amap工具的问题

code/chapter13/helloagents-trip-planner/backend/app/agents/trip_planner_agent.py

@@ -172,6 +172,7 @@ class MultiAgentTripPlanner:
                 env={"AMAP_MAPS_API_KEY": settings.amap_api_key},
                 auto_expand=True
             )
+            self.amap_tool.expandable=True
 
             # 创建景点搜索Agent
             print("  - 创建景点搜索Agent...")