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/components/StatusBar/StatusBar.tsx

@@ -1,18 +1,34 @@
 import React from 'react'
 import { useTabStore } from '../../stores/tabStore'
+import { useEditorStore } from '../../stores/editorStore'
 import { getFileName } from '../../lib/fileUtils'
+import { LoadingSpinner } from '../LoadingSpinner/LoadingSpinner'
 
-export function StatusBar() {
-  // B-04: 直接选择数据而非函数引用，确保响应式更新
-  const tabs = useTabStore(s => s.tabs)
-  const activeTabId = useTabStore(s => s.activeTabId)
-  const tab = tabs.find(t => t.id === activeTabId) ?? null
+export const StatusBar = React.memo(function StatusBar() {
+  const activeTab = useTabStore(s => s.getActiveTab())
+  const loadingStates = useEditorStore(s => s.loadingStates)
+
+  // 判断是否有任何加载状态激活
+  const hasLoading = Object.values(loadingStates).some(Boolean)
+  const loadingLabel = loadingStates['file-open']
+    ? '正在打开文件...'
+    : loadingStates['dir-load']
+      ? '正在加载目录...'
+      : loadingStates['markdown-render']
+        ? '正在渲染...'
+        : ''
 
   return (
     <div id="statusbar" role="status" aria-live="polite">
       <div className="status-left">
+        {hasLoading && (
+          <span className="status-loading" aria-busy="true">
+            <LoadingSpinner size="small" />
+            <span>{loadingLabel}</span>
+          </span>
+        )}
         <span id="status-text">
-          {tab ? (tab.filePath ? getFileName(tab.filePath) : '未命名') : '就绪'}
+          {activeTab ? (activeTab.filePath ? getFileName(activeTab.filePath) : '未命名') : '就绪'}
         </span>
       </div>
       <div className="status-right">
@@ -22,6 +38,6 @@ export function StatusBar() {
       </div>
     </div>
   )
-}
+})
 
-StatusBar.displayName = 'StatusBar'
+StatusBar.displayName = 'StatusBar'