Health

Unauthenticated liveness probe for Railway and the uptime monitor.

The failure branch answers with a fixed string rather than the driver's exception text. A SQLAlchemy connection error spells out the private-network DB host, port, role, and pool sizing, and nothing authenticates this route. The operator still gets the full detail, at error level in the service logs (and so in Sentry, via the logging integration).

Both branches keep answering 200. Railway's health check and the uptime monitor read the status code, so a DB blip must not read as a dead container and roll back a deploy. status is what separates them.