REST railing (Infra/VE/Health, tenant me): Same paths as Phoenix Deploy API; when PHOENIX_RAILING_URL is set, Sankofa API proxies to it. Full OpenAPI for the railing is in the phoenix-deploy-api repo (openapi.yaml). Tenant-scoped: GET /api/v1/tenants/me/resources, GET /api/v1/tenants/me/health (require JWT or X-API-Key with tenant).