feat(backend): AiGateway.generateQuestionnaire LangGraph 接入 + fallback mock + python.base-url 指向 ai.etotem.com.cn

cfc-backend/src/main/resources/application.yml

@@ -96,7 +96,7 @@ dify:
 
 python:
   enabled: true
-  base-url: http://localhost:9000
+  base-url: https://ai.etotem.com.cn
   timeout-ms: 15000
   circuit-breaker:
     failure-threshold: 3