✨ feat(vscode): 文件和文件夹在预览顶部问

侧栏「问 AI」打开代码阅读预览。文件夹是没有代码块的一页，源码文件在整页顶部聊，代码块下面的问答不动。历史按工作区文件夹和相对路径记在窗口状态里，不写进按块存的记录。

vscode/webview-ui/src/codeReader/App.tsx

@@ -6,6 +6,7 @@ import type { OccurrencePage } from './useOccurrences'
 import type { ViewState } from './viewState'
 import { TriangleAlert } from 'lucide-react'
 import { useCallback, useEffect, useMemo, useRef, useState } from 'react'
+import { AskThread } from './AskThread'
 import { BlockLevel } from './BlockTree'
 import { DiffBar, NewFileBanner } from './DiffBar'
 import { changeStops, diffTree, foldUnchanged, openedByDiff } from './diffView'
@@ -14,6 +15,7 @@ import { coveredByEditing, startEditing } from './editing'
 import { applyFilter, excludedBy, keptWhileEditing } from './filter'
 import { FilterBar } from './FilterBar'
 import { OverviewRuler } from './OverviewRuler'
+import { asksOf, historyOf, PATH_ASK_ANCHOR } from './qa'
 import { useChangeNav } from './useChangeNav'
 import { useDefinitionLinks } from './useDefinitionLinks'
 import { HighlightContext, useOccurrences } from './useOccurrences'
@@ -39,6 +41,8 @@ function savedBlockModes(): BlockModes {
 export function App(): ReactElement | null {
   // 先于下面发 ready 的那个 effect 挂上收消息：ready 后扩展端马上发问答
   const qa = useQa()
+  /** 侧栏「问 AI」要聚焦顶部输入框时加一 */
+  const [pathFocus, setPathFocus] = useState(0)
   /** 按注释规范重写的过程，只在这一页上 */
   const rewrites = useRewrite()
   const [doc, setDoc] = useState<DocumentMessage | null>(null)
@@ -121,6 +125,9 @@ export function App(): ReactElement | null {
           return
         case 'diff':
           setDiff(msg.diff)
+          return
+        case 'focusPathAsk':
+          setPathFocus(n => n + 1)
       }
     })
     postMessage({ type: 'ready' })
@@ -191,6 +198,25 @@ export function App(): ReactElement | null {
         />
         {changes && diff && <OverviewRuler stops={stops} lineCount={diff.lineCount} onPick={nav.goTo} />}
         <div className="mx-auto box-content max-w-[880px] px-6 py-5">
+          {qa.state.available && (
+            <div className="mb-4">
+              <AskThread
+                history={historyOf(qa.state, PATH_ASK_ANCHOR)}
+                asks={asksOf(qa.state, PATH_ASK_ANCHOR)}
+                open
+                hint={qa.state.subject === 'folder' ? '这个文件夹' : '这个文件'}
+                autoFocus={false}
+                focusToken={pathFocus}
+                closable={false}
+                profiles={qa.state.profiles}
+                onSelectProfile={qa.onSelectProfile}
+                onAsk={(question, images) => qa.onAsk(PATH_ASK_ANCHOR, question, images)}
+                onStop={qa.onStop}
+                onDelete={entryId => qa.onDelete(PATH_ASK_ANCHOR, entryId)}
+                onClose={() => undefined}
+              />
+            </div>
+          )}
           {diff?.newFile !== undefined && doc.error === undefined && <NewFileBanner detail={diff.newFile} />}
           {doc.error !== undefined && (
             <div className="mb-3 flex items-start gap-2 rounded-lg border border-[var(--vscode-inputValidation-errorBorder)] bg-[var(--vscode-inputValidation-errorBackground)] px-3 py-2">
@@ -205,7 +231,7 @@ export function App(): ReactElement | null {
             </div>
           )}
           {doc.blocks.length === 0
-            ? doc.error === undefined && <div className="text-[var(--vscode-descriptionForeground)]">这个文件里没有代码。</div>
+            ? doc.error === undefined && qa.state.subject !== 'folder' && <div className="text-[var(--vscode-descriptionForeground)]">这个文件里没有代码。</div>
             : doc.blocks.some(block => !filter.hidden.has(block.id))
               ? <BlockLevel blocks={doc.blocks} tree={tree} />
               : <div className="text-[var(--vscode-descriptionForeground)]">所有块都被筛选隐藏了。</div>}