CTO architectural ruling (PR #235 review): K8s readiness/liveness probes
must remain DB-less to prevent transient DB blips from cycling pods. The
/api/readyz endpoint (GRO-2687) is the canonical DB-health signal for the
monitoring layer and satisfies the GRO-2678 detection-gap requirement.
Removes:
- GET /health/ready route from src/index.ts
- src/__tests__/health-ready.test.ts
Refs GRO-2689, GRO-2687, GRO-2678