Readiness Probe

Kubernetes / ECS readiness probe — is the app ready to serve traffic?

Probes BOTH dependencies that auth + state-mutating requests need:

• PostgreSQL (request bodies, persistent state)
• Redis (token blacklist, account lockout, OAuth CSRF state)

A Redis outage in particular is silent for read traffic but breaks every login / refresh / OAuth flow — exactly the requests we want the ALB to stop sending us until Redis recovers. Without this check, the load balancer keeps pinning users to a degraded task.