refactor(frontend): hook for checking that user is logged in

frontend/src/hooks/use-auth-protection.tsx

@@ -0,0 +1,16 @@
+import { useCallback } from "react";
+import { useNavigate } from "react-router-dom";
+import { useAuth } from "./use-auth";
+
+export function useAuthProtection() {
+  const { user } = useAuth();
+  const navigate = useNavigate();
+
+  const requireUser = useCallback(async () => {
+    if (!user) {
+      navigate("/");
+    }
+  }, [user, navigate]);
+
+  return { requireUser };
+}