refactor: 优化组件并添加测试覆盖

- 创建 CLAUDE.md 项目开发指导文档
- 提取公共常量到 components/constants.ts
- 修复 TimestampToDatetime 重复插件扩展问题
- 修复 DatetimeToTimestamp 时区解析问题
- 优化 RoutePersistence 移除不必要依赖
- 添加 Vitest 测试框架配置
- 为所有组件编写单元测试 (16个测试用例)
- 更新 .gitignore 忽略测试结果目录

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

components/__tests__/RoutePersistence.test.tsx

@@ -0,0 +1,40 @@
+import { render } from '@testing-library/react';
+import { MemoryRouter } from 'react-router-dom';
+import RoutePersistence from '../RoutePersistence';
+import { storageUtil } from '@/utils/chromeStorage';
+import { vi } from 'vitest';
+
+vi.mock('@/utils/chromeStorage', () => ({
+  storageUtil: {
+    get: vi.fn(),
+    set: vi.fn(),
+  },
+}));
+
+const renderComponentOnly = (initialPath = '/') => {
+  return render(
+    <MemoryRouter initialEntries={[initialPath]}>
+      <RoutePersistence />
+    </MemoryRouter>,
+  );
+};
+
+describe('RoutePersistence', () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+  });
+
+  it('组件应该正常渲染且返回 null', () => {
+    const { container } = renderComponentOnly();
+    expect(container.firstChild).toBeNull();
+  });
+
+  it('当在根路由时应该从存储中恢复路由', async () => {
+    const mockGet = storageUtil.get as vi.Mock;
+    mockGet.mockResolvedValue('/timestamp');
+
+    await renderComponentOnly('/');
+
+    expect(mockGet).toHaveBeenCalledWith('app/lastRoute');
+  });
+});