fix(notifications): replace Cloud Run job with worker service

backend/command-api/src/worker-server.js

@@ -0,0 +1,12 @@
+import { createWorkerApp } from './worker-app.js';
+import { dispatchPendingNotifications } from './services/notification-dispatcher.js';
+
+const port = Number(process.env.PORT || 8080);
+const app = createWorkerApp({
+  dispatch: () => dispatchPendingNotifications(),
+});
+
+app.listen(port, () => {
+  // eslint-disable-next-line no-console
+  console.log(`krow-notification-worker listening on port ${port}`);
+});