Health Check Endpoints

Summary

A simple `/health` endpoint that reports whether your service (and its dependencies like the database) is up and working — used by load balancers and orchestrators to know if an instance should receive traffic.

• 1Add a `/health` endpoint that checks database connectivity, not just that the process is running.
• 2Learn the difference between liveness checks (is it running) and readiness checks (is it ready for traffic).
• 3Understand how orchestrators like Kubernetes use these to automatically restart unhealthy instances.