fix(GRO-1544): restore /health alongside /api/health endpoint

The previous GRO-1544 PR changed /health to /api/health but removed
the /health endpoint entirely. This breaks:
- Dockerfile HEALTHCHECK (curl -f http://localhost:3000/health)
- K8s readinessProbe/livenessProbe (httpGet: path: /health, port: 3000)

Both paths are registered before auth middleware so both remain
publicly accessible without authentication.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/index.ts

@@ -59,6 +59,9 @@ app.use(
 );
 
 // Health check — no auth required, registered on app at full path before auth middleware
+// /health: used by Dockerfile HEALTHCHECK and K8s readinessProbe/livenessProbe (port 3000 direct)
+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" }));
 
 // Public booking routes — no auth required, must be registered before auth middleware