前端项目初始化，登录页支持暗色主题与禁止滑动

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

frontend/src/pages/NotFoundPage.tsx

@@ -0,0 +1,19 @@
+import { Button, Result } from 'antd'
+import { useNavigate } from 'react-router-dom'
+
+export default function NotFoundPage() {
+  const navigate = useNavigate()
+
+  return (
+    <Result
+      status="404"
+      title="404"
+      subTitle="抱歉，您访问的页面不存在"
+      extra={
+        <Button type="primary" onClick={() => navigate('/')}>
+          返回首页
+        </Button>
+      }
+    />
+  )
+}