feat: Next.js 14 web admin scaffold — auth, sidebar, dashboard, placeholders

app/(app)/layout.tsx

@@ -0,0 +1,32 @@
+'use client';
+
+import { useEffect } from 'react';
+import { useRouter } from 'next/navigation';
+import { useAuthStore } from '@/lib/auth-store';
+import Sidebar from '@/components/layout/sidebar';
+import Topbar from '@/components/layout/topbar';
+
+export default function AppLayout({ children }: { children: React.ReactNode }) {
+  const router = useRouter();
+  const accessToken = useAuthStore((s) => s.accessToken);
+
+  useEffect(() => {
+    if (!accessToken) {
+      router.replace('/login');
+    }
+  }, [accessToken, router]);
+
+  if (!accessToken) {
+    return null;
+  }
+
+  return (
+    <div className="flex min-h-screen" style={{ backgroundColor: '#F8FAFC' }}>
+      <Sidebar />
+      <div className="flex-1 flex flex-col overflow-hidden">
+        <Topbar />
+        <main className="flex-1 overflow-y-auto p-6">{children}</main>
+      </div>
+    </div>
+  );
+}