Troubleshooting-agent API for the Devices app. Endpoints under /api require a
backoffice bearer token; /_health is anonymous. The user-facing UI is the devices admin app.
To exercise it directly, send a token obtained from the backoffice IdP:
curl -H "Authorization: Bearer <token>" -H "Content-Type: application/json" \
-X POST <host>/api/chat -d '{"message":"error rate for devices in the last 24h?"}'