ADD: added basic backend function plus a mockup for a cli interface

frontend/studia/src/components/ProtectedRoute.tsx

@@ -0,0 +1,10 @@
+import { Navigate } from "react-router-dom";
+import { useAuth } from "../components/AuthContext";
+import type { JSX } from 'react';
+
+const ProtectedRoute = ({ children }: { children: JSX.Element }) => {
+  const { token } = useAuth() as { token?: string | null };
+  return token ? children : <Navigate to="/" />;
+};
+
+export default ProtectedRoute;