feat: renamed old frontend and fixed some minor bugs

frontend/src/pages/auth/ProviderErrorPage/ProviderErrorPage.tsx

@@ -0,0 +1,10 @@
+import { useEffect } from "react";
+
+export const LoginProviderErrorPage = () => {
+  useEffect(() => {
+    window.localStorage.setItem("PROVIDER_AUTH_ERROR", "err");
+    window.close();
+  }, []);
+
+  return <div />;
+};

frontend/src/pages/auth/ProviderErrorPage/route.tsx

@@ -0,0 +1,7 @@
+import { createFileRoute } from "@tanstack/react-router";
+
+import { LoginProviderErrorPage } from "./ProviderErrorPage";
+
+export const Route = createFileRoute("/_restrict-login-signup/login/provider/error")({
+  component: LoginProviderErrorPage
+});