This FastAPI service is the server-only AI boundary for the Guangming travel POC. It defaults to deterministic `mock` mode. Model credentials belong only in `server/.env` or the deployment environment and must never be added to the mini-program build.
This service is reserved for a later AI integration phase. The current mini-program `createPlan` entry point is hard-wired to the local planner and does not call this service.
The response contains only POI IDs, reasons, and suggested order. In `custom` mode all 2-8 user-selected IDs are retained. The model never receives `origin`, and never owns coordinates, route geometry, transfer estimates, or final itinerary time; those remain deterministic client responsibilities.
`GET /api/v1/health` reports `mode` (`mock` or `real`), whether real-model credentials are `configured`, and whether the selected mode is `ready`.