v0.2.0: 全面代码质量优化

- ESLint flat config + Prettier + EditorConfig
- Markdown处理器LRU缓存
- Zustand选择器优化减少重渲染
- CodeMirror Compartment主题热切换
- Preview防抖(150ms) + IndexedDB去抖(500ms)
- 组件拆分: App.tsx 310→104行, Sidebar.tsx 244→90行
- 统一错误处理 errorHandler.ts
- ConfirmDialog替代原生confirm
- LoadingSpinner加载状态
- Toast多条堆叠+类型区分
- 可访问性增强(ARIA属性、键盘导航)
- Vitest测试框架(78个测试用例)
- Git hooks(husky + lint-staged)
- 项目文档(README.md, CONTRIBUTING.md)

src/renderer/hooks/useKeyboard.ts

@@ -1,7 +1,6 @@
 import { useEffect, useCallback } from 'react'
 import { useTabStore } from '../stores/tabStore'
 import { useEditorStore } from '../stores/editorStore'
-import type { ViewMode } from '../types/settings'
 
 export function useKeyboard(handleOpenFile: () => void, handleSave: () => void, handleSaveAs: () => void) {
   const setViewMode = useEditorStore(s => s.setViewMode)