✨ feat(vscode): 代码阅读预览按侧栏筛选算代码差异（未提交的更改对比上一次提交、审查对比 PR 目标分支；兄弟块按名字 / 相似度对齐，卡片内按行 / 值 / 词比对），算好后补发给预览

vscode/src/codeReader/uncommitted/uncommittedMode.ts

@@ -1,15 +1,18 @@
-import type { ExtensionContext, TreeView, WorkspaceFolder } from 'vscode'
+import type { ExtensionContext, TreeView, Uri, WorkspaceFolder } from 'vscode'
 import type { GitApi, GitRepository } from '../../git/gitApi'
+import type { DiffBase } from '../diff/diffBase'
 import type { ChangedFile } from '../explorer/changedTree'
 import type { ChangedSection, FileNode, FileTreeProvider, TreeNode } from '../explorer/fileTree'
 import type { TreeFilter, TreeFilters } from '../explorer/treeFilters'
 import type { UncommittedRoot } from './uncommittedFiles'
 import * as path from 'node:path'
 import { commands, Disposable, window, workspace } from 'vscode'
+import { fileAtRef } from '../../git/fileAt'
 import { loadGitApi } from '../../git/gitExtension'
 import { logger } from '../../logging/logger'
 import { buildChangedTree } from '../explorer/changedTree'
-import { uncommittedDescription, uncommittedMessage, uncommittedRoots, UNSTAGED_MARKER, withoutTestFiles, workspaceOrder } from './uncommittedFiles'
+import { toPathKey } from '../pathMap'
+import { HEAD_BASE_LABEL, headMissingText, isUntracked, uncommittedDescription, uncommittedMessage, uncommittedRoots, UNSTAGED_MARKER, withoutTestFiles, workspaceOrder } from './uncommittedFiles'
 
 /** workspaceState：开着「未提交的更改」，重开窗口接着显示。 */
 const UNCOMMITTED_KEY = 'superpowers.codeReader.uncommitted'
@@ -33,7 +36,7 @@ function errorText(err: unknown): string {
 /**
  * 侧栏只看未提交的更改：照源代码管理视图分「暂存的更改」「更改」两组（空的不摆），每组下面每个有改动的仓库一个根。
  * 文件就是工作区里的文件，颜色和 M / A / D 徽标由 VS Code 自带的 git 装饰加上；「更改」组里的文件行上有「暂存」按钮。
- * 可以隐藏测试文件。开着时盯着 git 状态自动重摆；「显示全部」回到工作区文件树。
+ * 可以隐藏测试文件。开着时盯着 git 状态自动重摆，打开的预览对比上一次提交（diffBase）；「显示全部」回到工作区文件树。
  * 开着没开、隐不隐藏测试文件都按工作区记住；和审查工单互斥，见 TreeFilters。
  */
 export class UncommittedMode implements TreeFilter, Disposable {
@@ -123,6 +126,24 @@ export class UncommittedMode implements TreeFilter, Disposable {
     }
   }
 
+  /** 开着时，工作区仓库里的文件对比上一次提交（HEAD）；不在工作区的仓库里（审查的工作副本、别处的文件）的不比。 */
+  diffBase(uri: Uri): DiffBase | undefined {
+    const repository = this.api?.getRepository(uri)
+    if (!repository || workspaceOrder(repository.rootUri.path, workspace.workspaceFolders ?? []) < 0)
+      return undefined
+    const relative = toPathKey(repository.rootUri.path, uri.path)
+    if (relative === undefined)
+      return undefined
+    const head = repository.state.HEAD?.commit
+    const root = repository.rootUri.fsPath
+    return {
+      label: HEAD_BASE_LABEL,
+      key: `${head ?? ''}:${relative}`,
+      read: () => head ? fileAtRef(root, head, relative) : Promise.resolve(null),
+      missing: headMissingText({ hasCommit: head !== undefined, untracked: isUntracked(repository.state, uri.path) }),
+    }
+  }
+
   dispose(): void {
     this.stopWatching()
     for (const disposable of this.disposables)
@@ -173,12 +194,18 @@ export class UncommittedMode implements TreeFilter, Disposable {
     }
   }
 
-  /** 盯着 git：各仓库的状态变了、开了 / 关了仓库、git 扩展找完仓库、工作区文件夹变了，都合成一次重摆。 */
+  /**
+   * 盯着 git：各仓库的状态变了、开了 / 关了仓库、git 扩展找完仓库、工作区文件夹变了，都合成一次重摆；
+   * 打开着的预览也跟着重新比（提交后 HEAD 动了，对比的上一次提交就换了）。
+   */
   private watch(api: GitApi): Disposable {
     const repositories = new Map<GitRepository, Disposable>()
     const schedule = (): void => {
       clearTimeout(this.timer)
-      this.timer = setTimeout(() => this.rebuild(), REBUILD_DELAY_MS)
+      this.timer = setTimeout(() => {
+        this.rebuild()
+        this.filters.baseChanged(this)
+      }, REBUILD_DELAY_MS)
     }
     const add = (repository: GitRepository): void => {
       if (!repositories.has(repository))