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__/TimestampExecution.test.tsx

@@ -0,0 +1,39 @@
+import { render, screen, fireEvent } from '@testing-library/react';
+import { TimestampExecution } from '../TimestampExecution';
+import { vi } from 'vitest';
+
+describe('TimestampExecution', () => {
+  beforeEach(() => {
+    vi.useFakeTimers();
+  });
+
+  afterEach(() => {
+    vi.useRealTimers();
+  });
+
+  it('应该正确渲染组件', () => {
+    render(<TimestampExecution />);
+    expect(screen.getByText('切换单位')).toBeInTheDocument();
+    expect(screen.getByText('复制')).toBeInTheDocument();
+    expect(screen.getByText('停止')).toBeInTheDocument();
+  });
+
+  it('初始状态应该显示毫秒单位', () => {
+    render(<TimestampExecution />);
+    expect(screen.getByText('毫秒')).toBeInTheDocument();
+  });
+
+  it('点击切换单位按钮应该切换为秒显示', () => {
+    render(<TimestampExecution />);
+    const toggleUnitButton = screen.getByText('切换单位');
+    fireEvent.click(toggleUnitButton);
+    expect(screen.getByText('秒')).toBeInTheDocument();
+  });
+
+  it('点击停止按钮应该停止时间戳自动更新', () => {
+    render(<TimestampExecution />);
+    const toggleButton = screen.getByText('停止');
+    fireEvent.click(toggleButton);
+    expect(screen.getByText('开始')).toBeInTheDocument();
+  });
+});