✨ 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/src/codeReader/qa/pathQa.ts

@@ -0,0 +1,97 @@
+/**
+ * 预览顶部的问答：按「工作区文件夹 + 相对路径」记在这个窗口的 workspaceState 里。
+ * 文件和文件夹各用各的路径；不写进按块存的 `.spx/code-qa.json`。
+ */
+
+import type { QaEntry } from './qaMap'
+import * as path from 'node:path'
+import { normalizeKey } from '../pathMap'
+
+/** workspaceState 里这份表的键 */
+export const PATH_QA_STATE_KEY = 'codeReader.pathQa'
+
+/**
+ * 顶部这一轮的记号。块的记号是「种类 名字」，不会是这个，
+ * 所以页面上按记号取问答时，顶部的不会挂到某一块下面。
+ */
+export const PATH_ASK_ANCHOR = '\0path'
+
+/** 工作区文件夹 Uri → 那条路径上的问答（按问的先后） */
+export type PathQaMap = Record<string, QaEntry[]>
+
+/** 工作区根的相对路径是空字符串，跟任何一个文件或子目录都不同。 */
+export function relativeQaKey(rootPath: string, targetPath: string): string | undefined {
+  const relative = path.posix.relative(rootPath, targetPath)
+  if (relative === '')
+    return ''
+  return normalizeKey(relative)
+}
+
+/** 同一工作区文件夹、同一相对路径才是同一条记录。 */
+export function pathQaKey(folderUri: string, relativePath: string): string {
+  return `${folderUri}\n${relativePath}`
+}
+
+/** 给人看的相对路径；工作区根写成 `.`。 */
+export function displayRelativePath(relativePath: string): string {
+  return relativePath === '' ? '.' : relativePath
+}
+
+export function pathQaEntries(map: PathQaMap, key: string): QaEntry[] {
+  return map[key] ?? []
+}
+
+/** 新的一次问答接在这条路径已有的后面，别的路径不动。 */
+export function withPathQa(map: PathQaMap, key: string, entry: QaEntry): PathQaMap {
+  return { ...map, [key]: [...pathQaEntries(map, key), entry] }
+}
+
+/** 删掉这一次；这条路径问光了就把键拿掉。没有这一次时原样返回。 */
+export function withoutPathQa(map: PathQaMap, key: string, entryId: string): PathQaMap {
+  const entries = pathQaEntries(map, key)
+  const kept = entries.filter(entry => entry.id !== entryId)
+  if (kept.length === entries.length)
+    return map
+  if (kept.length === 0) {
+    const next = { ...map }
+    delete next[key]
+    return next
+  }
+  return { ...map, [key]: kept }
+}
+
+/** 读 workspaceState 里存的表；认不出的丢掉，不让一条坏数据把整份弄丢。 */
+export function parsePathQa(value: unknown): PathQaMap {
+  if (!isRecord(value))
+    return {}
+  const map: PathQaMap = {}
+  for (const [key, entries] of Object.entries(value)) {
+    if (!Array.isArray(entries))
+      continue
+    const parsed = entries.flatMap((entry) => {
+      const one = parseEntry(entry)
+      return one ? [one] : []
+    })
+    if (parsed.length > 0)
+      map[key] = parsed
+  }
+  return map
+}
+
+function parseEntry(value: unknown): QaEntry | undefined {
+  if (!isRecord(value))
+    return undefined
+  const { id, question, answer, createdAt, sessionId, profile, images } = value
+  if (typeof id !== 'string' || typeof question !== 'string' || typeof answer !== 'string' || typeof createdAt !== 'string' || typeof sessionId !== 'string')
+    return undefined
+  const entry: QaEntry = { id, question, answer, createdAt, sessionId }
+  if (typeof profile === 'string' && profile !== '')
+    entry.profile = profile
+  if (Array.isArray(images) && images.every(name => typeof name === 'string'))
+    entry.images = images
+  return entry
+}
+
+function isRecord(value: unknown): value is Record<string, unknown> {
+  return typeof value === 'object' && value !== null && !Array.isArray(value)
+}