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>

tsconfig.vitest.json

@@ -0,0 +1,18 @@
+{
+  "extends": "./tsconfig.json",
+  "compilerOptions": {
+    "types": ["vitest/globals", "node"],
+    "jsx": "react-jsx",
+    "skipLibCheck": true,
+    "moduleResolution": "bundler",
+    "resolveJsonModule": true
+  },
+  "include": [
+    "components/**/*.test.tsx",
+    "components/**/*.tsx",
+    "components/**/*.ts",
+    "utils/**/*.ts",
+    "utils/**/*.tsx",
+    "vitest.setup.ts"
+  ]
+}