♻️ fix(vscode): 「已查看」改为按文件变更指纹失效，PR 新 push 只摘变动文件的勾

原先按 head sha 存已查看，作者一推新提交 head sha 变了，全部勾一起清空——
哪怕只改了一个文件也把没动的勾全冲掉。改成 GitHub「Viewed」式的内容感知：
按每个文件的变更指纹 (status|additions|deletions) 存，拉文件时与当前指纹比对，
只有真改动过的文件掉勾，没动的保留；比对后顺手剪掉盘上失配/消失的条目。

Gitea 的 ChangedFile 不返回 blob sha、compare 端点也不支持任意 commit sha，
故用上述三元组作指纹（文件一改几乎必变其一），零额外请求。

- prReviewStore: 形状改为 issueNumber → {path: sig}，导出 read/writeConfirmedSigs
- prFiles: handleGetPrFiles 按指纹过滤+剪枝，顺带去掉不再需要的 getPullRequest 调用
- 消息 pr-files/show 去掉无人消费的 headSha/mergeBase；pr-review/set 改发 {path: sig}
- usePrFiles: 删 headSha，setConfirmed 把路径映射成指纹再发

vscode/src/panel/handlers/prFiles.ts

@@ -3,8 +3,9 @@
  * 单个文件改动前后的原文，交给 webview 内联渲染（主从式 diff）。
  *
  * 数据全程实时拉取，只把「已查看」确认态落到 `.spx/pr-review-confirmed.json`
- * （键含 head sha，新 push 自然重置）。diff 左右两侧用 merge_base → head 的原文，
- * 与 Gitea 网页 diff 口径一致；getRawFile 对 404 兜底空串，故新增/删除/改名天然成立。
+ * （按文件变更指纹失效：作者推新提交后，仅真改动过的文件掉勾，没动的保留）。diff
+ * 左右两侧用 merge_base → head 的原文，与 Gitea 网页 diff 口径一致；getRawFile 对
+ * 404 兜底空串，故新增/删除/改名天然成立。
  */
 
 import type { KanbanWebviewPanel } from '../KanbanPanel'
@@ -17,7 +18,7 @@ import { detectRepo } from '../../git/remote'
 import { getPullRequest, getRawFile, listPullRequestFiles } from '../../gitea/api'
 import { readStateJsonComment } from '../../gitea/stateJson'
 import { readFileSummaries, readSummarySession, writeFileSummary, writeSummarySession } from '../../sessions/prFileSummaryStore'
-import { readConfirmed, writeConfirmed } from '../../sessions/prReviewStore'
+import { readConfirmedSigs, writeConfirmedSigs } from '../../sessions/prReviewStore'
 import { makeNonce } from '../KanbanPanel'
 
 /**
@@ -103,27 +104,33 @@ function langFromPath(path: string): string {
   return map[ext] ?? ext
 }
 
+/** 文件「变更指纹」：内容一改，status/additions/deletions 几乎必变其一；用于判定已查看是否仍有效。 */
+function fileSig(f: { status: string, additions: number, deletions: number }): string {
+  return `${f.status}|${f.additions}|${f.deletions}`
+}
+
 /**
- * 拉取工单对应 PR 的全部改动文件清单 + head/mergeBase ref + 已确认集合，推给 webview。
+ * 拉取工单对应 PR 的全部改动文件清单 + 已查看集合 + 已生成说明，推给 webview。
  * 无 PR/缺上下文回空（前端按空态处理）；真出错才带 error。
+ *
+ * 已查看按「变更指纹」判定：取每个文件当前的 status|additions|deletions，与落盘记录的
+ * 指纹比对，仅相符的文件仍算已查看——作者推新提交后只有真改动过的文件掉勾。比对后顺手把
+ * 已失配/已消失的条目从盘上剪掉。
  */
 export async function handleGetPrFiles(panel: KanbanWebviewPanel, issueNumber: number): Promise<void> {
   try {
     const ctx = await resolveRepoContext(panel)
     if (!ctx) {
-      panel.postMessage({ type: 'pr-files/show', issueNumber, headSha: '', mergeBase: '', files: [], confirmed: [], summaries: {} })
+      panel.postMessage({ type: 'pr-files/show', issueNumber, files: [], confirmed: [], summaries: {} })
       return
     }
 
     const index = await resolvePrNumber(ctx, issueNumber)
     if (index === undefined) {
-      panel.postMessage({ type: 'pr-files/show', issueNumber, headSha: '', mergeBase: '', files: [], confirmed: [], summaries: {} })
+      panel.postMessage({ type: 'pr-files/show', issueNumber, files: [], confirmed: [], summaries: {} })
       return
     }
 
-    const pr = await getPullRequest({ host: ctx.host, owner: ctx.owner, repo: ctx.repo, token: ctx.token, index })
-    // 三点 diff 的左侧 ref：优先 merge_base，缺失则退回 base sha。
-    const mergeBase = pr.mergeBase || pr.baseSha
     const files = await listPullRequestFiles({
       host: ctx.host,
       owner: ctx.owner,
@@ -131,29 +138,34 @@ export async function handleGetPrFiles(panel: KanbanWebviewPanel, issueNumber: n
       token: ctx.token,
       index,
     })
+
     const workspaceRoot = workspace.workspaceFolders?.[0]?.uri.fsPath
-    const [confirmed, summaries] = workspaceRoot
-      ? await Promise.all([
-          readConfirmed(workspaceRoot, issueNumber, pr.headSha),
-          readFileSummaries(workspaceRoot, issueNumber),
-        ])
-      : [[], {}]
-    panel.postMessage({
-      type: 'pr-files/show',
-      issueNumber,
-      headSha: pr.headSha,
-      mergeBase,
-      files,
-      confirmed,
-      summaries,
-    })
+    let confirmed: string[] = []
+    let summaries: Record<string, string> = {}
+    if (workspaceRoot) {
+      const [stored, sums] = await Promise.all([
+        readConfirmedSigs(workspaceRoot, issueNumber),
+        readFileSummaries(workspaceRoot, issueNumber),
+      ])
+      summaries = sums
+      // 当前每文件的变更指纹；仅指纹相符的已查看条目仍有效。
+      const cur = new Map(files.map(f => [f.path, fileSig(f)]))
+      confirmed = Object.keys(stored).filter(p => cur.get(p) === stored[p])
+      // 有失配/消失才写盘，剪掉陈旧条目，避免无谓磁盘写入。
+      if (confirmed.length !== Object.keys(stored).length) {
+        const pruned: Record<string, string> = {}
+        for (const p of confirmed)
+          pruned[p] = stored[p]
+        await writeConfirmedSigs(workspaceRoot, issueNumber, pruned)
+      }
+    }
+
+    panel.postMessage({ type: 'pr-files/show', issueNumber, files, confirmed, summaries })
   }
   catch (err) {
     panel.postMessage({
       type: 'pr-files/show',
       issueNumber,
-      headSha: '',
-      mergeBase: '',
       files: [],
       confirmed: [],
       summaries: {},
@@ -212,19 +224,18 @@ export async function handleGetPrFileDiff(
 }
 
 /**
- * 持久化某 PR 里已确认（已审阅）的文件路径集合到 `.spx/pr-review-confirmed.json`，
- * 键含 head sha。拿不到工作区根则静默跳过；写盘失败兜底打日志、不抛——确认态丢失
- * 不该中断 UI。
+ * 持久化某 PR 的「已查看文件 → 变更指纹」映射到 `.spx/pr-review-confirmed.json`。
+ * 拿不到工作区根则静默跳过；写盘失败兜底打日志、不抛——确认态丢失不该中断 UI。
  */
 export async function handleSetPrReviewConfirmed(
-  panel: KanbanWebviewPanel,
-  args: { issueNumber: number, headSha: string, confirmed: string[] },
+  _panel: KanbanWebviewPanel,
+  args: { issueNumber: number, confirmed: Record<string, string> },
 ): Promise<void> {
   try {
     const workspaceRoot = workspace.workspaceFolders?.[0]?.uri.fsPath
     if (!workspaceRoot)
       return
-    await writeConfirmed(workspaceRoot, args.issueNumber, args.headSha, args.confirmed)
+    await writeConfirmedSigs(workspaceRoot, args.issueNumber, args.confirmed)
   }
   catch (err) {
     console.warn('handleSetPrReviewConfirmed 写盘失败', err)

vscode/src/panel/messages.ts

@@ -100,7 +100,7 @@ export type ExtensionToWebview
     | { type: 'issue/remove', issueNumber: number }
     | { type: 'profiles/show', data: ProfilesData }
     | { type: 'managed-sessions/show', data: ManagedSessionsShowData }
-    | { type: 'pr-files/show', issueNumber: number, headSha: string, mergeBase: string, files: PrFile[], confirmed: string[], summaries: Record<string, string>, error?: string }
+    | { type: 'pr-files/show', issueNumber: number, files: PrFile[], confirmed: string[], summaries: Record<string, string>, error?: string }
     | { type: 'pr-file-diff/show', issueNumber: number, path: string, oldContent: string, newContent: string, oldLang?: string, newLang?: string, error?: string }
     | { type: 'pr-file-summary/show', issueNumber: number, path: string, summary?: string, error?: string }
 
@@ -176,4 +176,4 @@ export type WebviewToExtension
     | { type: 'pr-files/get', issueNumber: number }
     | { type: 'pr-file-diff/get', issueNumber: number, path: string, previousPath?: string }
     | { type: 'pr-file-summary/generate', issueNumber: number, path: string, previousPath?: string }
-    | { type: 'pr-review/set', issueNumber: number, headSha: string, confirmed: string[] }
+    | { type: 'pr-review/set', issueNumber: number, confirmed: Record<string, string> }