✨ feat(vscode): 「改动」tab 重做为整 PR 聚合的主从式内联 diff（git-diff-view）

- 左树右 diff：左栏全 PR 文件树 + 统计条（共改 N · +X−Y · 已查看 M/N），右栏选中单文件内联 diff
- 用 @git-diff-view/react 只渲染当前选中文件，绕开上万行全量渲染的性能坑
- gitea 新增 listPullRequestFiles、getPullRequest 取 merge_base/head，按需回两版原文
- diff 走 merge_base→head 三点口径（与 Gitea 网页一致），getRawFile 404 兜底成全增/全删/改名
- 已查看态按 head sha 落盘、新 push 自然重置；去掉提交列表、原生 diff 与 spx-gitea 虚拟文档 provider

vscode/webview-ui/src/lib/messages.ts

@@ -11,18 +11,16 @@ export interface ToastLink {
   url: string
 }
 
-/** PR 提交的精简视图（提交列表渲染用）。 */
-export interface PrCommit {
-  sha: string
-  message: string
-  authorName: string
-  date: string
-}
-
-/** 提交内单个文件改动：status 取 added/modified/deleted/renamed/copied 等。 */
-export interface PrCommitFile {
+/**
+ * PR 改动里的一个文件：status 取 added/modified/deleted/renamed/copied 等，
+ * additions/deletions 求和成统计条，previousFilename 在改名时给出旧路径。
+ */
+export interface PrFile {
   path: string
   status: string
+  additions: number
+  deletions: number
+  previousFilename?: string
 }
 
 export type ToastLevel = 'info' | 'success' | 'error'
@@ -117,8 +115,8 @@ export type ExtensionToWebview
     | { type: 'issue/remove', issueNumber: number }
     | { type: 'profiles/show', data: ProfilesData }
     | { type: 'managed-sessions/show', data: ManagedSessionsData }
-    | { type: 'pr-commits/show', issueNumber: number, commits: PrCommit[], confirmedCommits: string[], error?: string }
-    | { type: 'pr-commit-files/show', issueNumber: number, sha: string, parentSha?: string, files: PrCommitFile[], confirmed: string[], error?: string }
+    | { type: 'pr-files/show', issueNumber: number, headSha: string, mergeBase: string, files: PrFile[], confirmed: string[], error?: string }
+    | { type: 'pr-file-diff/show', issueNumber: number, path: string, oldContent: string, newContent: string, oldLang?: string, newLang?: string, error?: string }
 
 export type WebviewToExtension
   = | { type: 'issues/refresh' }
@@ -189,8 +187,6 @@ export type WebviewToExtension
     | { type: 'managed-sessions/resume', sessionId: string }
     | { type: 'managed-sessions/delete', sessionId: string }
     | { type: 'managed-sessions/close-tab', sessionId: string }
-    | { type: 'pr-commits/get', issueNumber: number }
-    | { type: 'pr-commit-files/get', issueNumber: number, sha: string }
-    | { type: 'pr-commit-diff/open', issueNumber: number, sha: string, parentSha?: string, path: string, status: string }
-    | { type: 'pr-review/set', issueNumber: number, sha: string, confirmed: string[] }
-    | { type: 'pr-review/set-commits', issueNumber: number, confirmed: string[] }
+    | { type: 'pr-files/get', issueNumber: number }
+    | { type: 'pr-file-diff/get', issueNumber: number, path: string, previousPath?: string }
+    | { type: 'pr-review/set', issueNumber: number, headSha: string, confirmed: string[] }