feat(tess): add safe runtime observability (#726)

apps/gateway/src/health/health.controller.test.ts

@@ -0,0 +1,12 @@
+import { describe, expect, it } from 'vitest';
+import { HealthController } from './health.controller.js';
+
+describe('HealthController', (): void => {
+  it('exposes liveness and readiness without configuration details', (): void => {
+    const controller = new HealthController();
+
+    expect(controller.check()).toEqual({ status: 'ok' });
+    expect(controller.ready()).toEqual({ status: 'ready' });
+    expect(JSON.stringify(controller.ready())).not.toContain('credential');
+  });
+});