first commit

frontend/app/page.tsx

@@ -0,0 +1,16 @@
+"use client";
+import { useEffect } from "react";
+import { useRouter } from "next/navigation";
+
+export default function RootPage() {
+  const router = useRouter();
+
+  useEffect(() => {
+    const hasToken = document.cookie.includes("accessToken");
+    if (!hasToken) {
+      window.location.href = "/login.html";
+    } else {
+      router.push("/main/overview/dashboard");
+    }
+  }, [router]);
+}