revert(api): remove /health/ready — superseded by /api/readyz (GRO-2689)

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

src/index.ts

@@ -65,17 +65,6 @@ app.use(
 app.get("/health", (c) => c.json({ status: "ok" }));
 // /api/health: used by Gateway HTTPRoute (/api/* → API pod)
 app.get("/api/health", (c) => c.json({ status: "ok" }));
-// /health/ready: DB-touching readiness probe — K8s removes pod from endpoints when schema is dropped (GRO-2689)
-app.get("/health/ready", async (c) => {
-  try {
-    await getDb().select({ id: staff.id }).from(staff).limit(1);
-    return c.json({ status: "ready" }, 200);
-  } catch (err) {
-    const pgCode = (err as Record<string, unknown>).code ?? "unknown";
-    console.error("[health/ready] DB check failed:", pgCode);
-    return c.json({ status: "degraded" }, 503);
-  }
-});
 // /api/readyz: DB-touching deep health check consumed by monitoring (not K8s probes)
 // Distinct from /health so a dropped schema triggers an alert without cycling pods (GRO-2678)
 app.get("/api/readyz", async (c) => {