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__/CopyButton.test.tsx

@@ -0,0 +1,52 @@
+import { render, screen, fireEvent } from '@testing-library/react';
+import CopyButton from '../CopyButton';
+import { vi } from 'vitest';
+
+describe('CopyButton', () => {
+  beforeEach(() => {
+    vi.useFakeTimers();
+  });
+
+  afterEach(() => {
+    vi.useRealTimers();
+    vi.clearAllMocks();
+  });
+
+  it('应该正确渲染默认文本', () => {
+    render(<CopyButton textToCopy="test" />);
+    expect(screen.getByText('复制')).toBeInTheDocument();
+  });
+
+  it('应该正确渲染自定义按钮文本', () => {
+    render(<CopyButton textToCopy="test" buttonText="Custom Copy" />);
+    expect(screen.getByText('Custom Copy')).toBeInTheDocument();
+  });
+
+  it('点击按钮时应该复制文本到剪贴板', async () => {
+    const writeTextMock = vi.fn().mockResolvedValue(undefined);
+    Object.defineProperty(navigator, 'clipboard', {
+      value: { writeText: writeTextMock },
+      writable: true,
+    });
+
+    render(<CopyButton textToCopy="test content" />);
+    const button = screen.getByText('复制');
+
+    fireEvent.click(button);
+    vi.advanceTimersByTime(300);
+
+    expect(writeTextMock).toHaveBeenCalledWith('test content');
+  });
+
+  it('当没有提供要复制的文本时，应该在控制台警告', async () => {
+    const consoleWarnSpy = vi.spyOn(console, 'warn').mockImplementation(() => {});
+
+    render(<CopyButton textToCopy="" />);
+    const button = screen.getByText('复制');
+
+    fireEvent.click(button);
+
+    expect(consoleWarnSpy).toHaveBeenCalledWith('没有提供要复制的文本');
+    consoleWarnSpy.mockRestore();
+  });
+});