Phase 5: ship (healthz, CI test gates, v1.0 README)

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

server/src/index.ts

@@ -34,6 +34,10 @@ app.use(pinoHttp({ logger }));
 app.use(cors({ origin: process.env.CLIENT_URL || 'http://localhost:5173' }));
 app.use(express.json());
 
+app.get('/healthz', (_req, res) => {
+  res.json({ status: 'ok' });
+});
+
 const loginLimiter = rateLimit({
   windowMs: 15 * 60 * 1000,
   max: 10,