ADD: added initial page with login

frontend/src/pages/ProtectedRoute.tsx

@@ -0,0 +1,8 @@
+import { Navigate } from 'react-router-dom';
+import { useAuth } from './AuthContext';
+import { JSX } from 'react';
+
+export default function ProtectedRoute({ children }: { children: JSX.Element }) {
+  const { token } = useAuth();
+  return token ? children : <Navigate to="/login" replace />;
+}