- Add docs/development/api-documentation.md describing the Swagger UI layout,
per-center grouping, auth headers, and production exposure.
- Add a `make openapi` target + dc3/bin/export_openapi.sh to snapshot each
center's OpenAPI JSON from a running stack.
- Update AGENTS.md: OpenAPI/Swagger conventions, and correct the enum-suffix
examples (multi-valued sets use *TypeEnum, not *FlagEnum).
