feat: 添加私有状态处理及私有页面组件

src/pages/Private.tsx

@@ -0,0 +1,29 @@
+import { Button } from "@/components/ui/button";
+import {
+  Card,
+  CardDescription,
+  CardFooter,
+  CardHeader,
+  CardTitle,
+} from "@/components/ui/card";
+import { useNavigate } from "react-router-dom";
+
+export default function Private() {
+  const navigate = useNavigate();
+
+  return (
+    <div className="fixed inset-0 flex items-center justify-center">
+      <Card className="w-full max-w-md">
+        <CardHeader>
+          <CardTitle className="text-2xl font-bold">站点已设为私有</CardTitle>
+          <CardDescription>登录后才能获取数据</CardDescription>
+        </CardHeader>
+        <CardFooter>
+          <Button onClick={() => navigate("/admin")} className="w-full">
+            前往登录
+          </Button>
+        </CardFooter>
+      </Card>
+    </div>
+  );
+}