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/constants.ts

@@ -0,0 +1,28 @@
+export const TIME_ZONE_LIST = [
+  'America/New_York',
+  'America/Chicago',
+  'America/Denver',
+  'America/Los_Angeles',
+  'America/Anchorage',
+  'America/Honolulu',
+  'Europe/London',
+  'Europe/Paris',
+  'Europe/Berlin',
+  'Europe/Moscow',
+  'Asia/Tokyo',
+  'Asia/Shanghai',
+  'Asia/Hong_Kong',
+  'Asia/Singapore',
+  'Asia/Dubai',
+  'Asia/Kolkata',
+  'Australia/Sydney',
+  'Pacific/Auckland',
+] as const;
+
+export const TIMESTAMP_UNITS = [
+  { value: 'milliseconds', label: '毫秒 (ms)' },
+  { value: 'seconds', label: '秒 (s)' },
+] as const;
+
+export type TimeZone = (typeof TIME_ZONE_LIST)[number];
+export type TimestampUnit = (typeof TIMESTAMP_UNITS)[number]['value'];