✨ feat(vscode): 代码阅读预览界面

Vite 加 code-reader.html 第二入口；代码块树（层级竖线、折叠、种类标签配色）、译文 / 源码按词性着色、块内直接编辑（防抖回写整行、Esc 回预览）、翻译下拉、解析失败提示；看板与代码阅读共用带类型的 acquireVsCodeApi 包装和 ErrorBoundary。

vscode/webview-ui/src/main.tsx

@@ -1,45 +1,9 @@
 import React from 'react'
 import ReactDOM from 'react-dom/client'
 import { App } from './App'
+import { ErrorBoundary } from './components/ErrorBoundary'
 import './index.css'
 
-// ponytail: 无此 boundary 时，任意渲染异常都会让整个 React 树卸载成空白面板
-// （用户报告"用着用着突然啥都没了"）。捕获后显示错误+重载按钮，免得只能整窗重载。
-interface BoundaryState { error: Error | null }
-class ErrorBoundary extends React.Component<{ children: React.ReactNode }, BoundaryState> {
-  state: BoundaryState = { error: null }
-
-  static getDerivedStateFromError(error: Error): BoundaryState {
-    return { error }
-  }
-
-  componentDidCatch(error: Error, info: React.ErrorInfo): void {
-    console.error('[superpowers webview] render crash:', error, info.componentStack)
-  }
-
-  render(): React.ReactNode {
-    const { error } = this.state
-    if (!error)
-      return this.props.children
-    return (
-      <div className="flex h-full w-full flex-col items-center justify-center gap-3 p-6 text-center text-[var(--vscode-foreground)]">
-        <div className="text-sm font-semibold text-[var(--vscode-errorForeground)]">面板渲染出错</div>
-        <pre className="max-h-60 max-w-full overflow-auto whitespace-pre-wrap text-left text-xs text-[var(--vscode-descriptionForeground)]">
-          {error.message}
-          {error.stack ? `\n\n${error.stack}` : ''}
-        </pre>
-        <button
-          type="button"
-          onClick={() => window.location.reload()}
-          className="rounded bg-[var(--vscode-button-background)] px-3 py-1 text-xs text-[var(--vscode-button-foreground)] hover:bg-[var(--vscode-button-hoverBackground)]"
-        >
-          重新加载
-        </button>
-      </div>
-    )
-  }
-}
-
 ReactDOM.createRoot(document.getElementById('root')!).render(
   <React.StrictMode>
     <ErrorBoundary>