chore: basic layout

src/routes/_app/alarm.tsx

@@ -0,0 +1,9 @@
+import { createFileRoute } from '@tanstack/react-router';
+
+export const Route = createFileRoute('/_app/alarm')({
+  component: AlarmPage,
+});
+
+function AlarmPage() {
+  return <div>Hello "/_app/alarm"!</div>;
+}