Fix App.jsx: remove dead comment, make auth state reactive

- Remove leftover commented-out AdminDashboard import
- Replace static localStorage reads with useState + useEffect
  so isLoggedIn/role update automatically on storage events
  (e.g. token deleted in another tab)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/src/App.jsx

@@ -1,5 +1,5 @@
 import { BrowserRouter, Navigate, Route, Routes } from 'react-router-dom';
-//import AdminDashboard from './components/AdminDashboard';
+import { useState, useEffect } from 'react';
 import LoginForm from './components/LoginForm';
 //import RegisterForm from './components/RegisterForm';
 import Md5Tool from './components/Md5Tool';
@@ -24,8 +24,17 @@ import './css/admin.css';
 
 
 function App() {
-  const isLoggedIn = localStorage.getItem('token') !== null;
+  const [isLoggedIn, setIsLoggedIn] = useState(localStorage.getItem('token') !== null);
-  const role = localStorage.getItem('role');
+  const [role, setRole] = useState(localStorage.getItem('role'));
+
+  useEffect(() => {
+    const sync = () => {
+      setIsLoggedIn(localStorage.getItem('token') !== null);
+      setRole(localStorage.getItem('role'));
+    };
+    window.addEventListener('storage', sync);
+    return () => window.removeEventListener('storage', sync);
+  }, []);
 
   return (
     <ErrorBoundary>