fix: 修复 Popover 导入缺失问题

- 添加缺失的 Popover 组件导入
- 确保时间选择器正常运行

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/pages/HomePage.tsx

@@ -13,6 +13,7 @@ import {
   Stack,
   Box,
   ActionIcon,
+  Popover,
 } from '@mantine/core';
 import { DatePickerInput } from '@mantine/dates';
 import { IconCalendar, IconClock, IconSettings, IconLogout, IconX } from '@tabler/icons-react';