feat(api): complete unified v2 mobile surface

backend/core-api/src/routes/health.js

@@ -1,4 +1,5 @@
 import { Router } from 'express';
+import { checkDatabaseHealth, isDatabaseConfigured } from '../services/db.js';
 
 export const healthRouter = Router();
 
@@ -13,3 +14,31 @@ function healthHandler(req, res) {
 
 healthRouter.get('/health', healthHandler);
 healthRouter.get('/healthz', healthHandler);
+
+healthRouter.get('/readyz', async (req, res) => {
+  if (!isDatabaseConfigured()) {
+    return res.status(503).json({
+      ok: false,
+      service: 'krow-core-api',
+      status: 'DATABASE_NOT_CONFIGURED',
+      requestId: req.requestId,
+    });
+  }
+
+  const healthy = await checkDatabaseHealth().catch(() => false);
+  if (!healthy) {
+    return res.status(503).json({
+      ok: false,
+      service: 'krow-core-api',
+      status: 'DATABASE_UNAVAILABLE',
+      requestId: req.requestId,
+    });
+  }
+
+  return res.status(200).json({
+    ok: true,
+    service: 'krow-core-api',
+    status: 'READY',
+    requestId: req.requestId,
+  });
+});