✨ feat(vscode): 「改动」面板加审查勾 + deepseek 增量生成文件改动说明

右栏 diff 头部加一组按钮:
- 审查对勾:与左树同一状态源,勾上则文件路径标题置灰
- ✨ 一键调 deepseek 生成该文件「一句话改动目的」

增量复用会话:首个文件开新 cc 会话并把 sessionId 记到
.spx/pr-file-summaries.json,后续文件 --resume 接上去,省去每次重新
理解 PR 的开销;resume 失败则丢弃旧 id 重开一次。说明也落盘(跨 push
保留),重载后仍显示。

- spawnClaude 增 resumeSessionId(--resume)
- 新增 prFileSummaryStore;handler handleGeneratePrFileSummary
  用 jsdiff 拼 unified diff 喂模型
- 依赖 diff(jsdiff)

vscode/src/cc/spawnClaude.ts

@@ -234,14 +234,16 @@ export async function spawnClaude(opts: {
   images?: ClaudeImage[]
   profilePath?: string
   bare?: boolean
+  /** 续会话：传入则 `--resume <id>`，让本次 `-p` 接在该会话之后（复用上下文，省 token）。 */
+  resumeSessionId?: string
 }): Promise<ClaudeResult> {
   const timeoutMs = opts.timeoutMs ?? DEFAULT_TIMEOUT_MS
   const hasImages = !!opts.images && opts.images.length > 0
 
   if (!hasImages) {
-    return spawnClaudeText(opts.prompt, opts.cwd, timeoutMs, opts.profilePath, opts.bare)
+    return spawnClaudeText(opts.prompt, opts.cwd, timeoutMs, opts.profilePath, opts.bare, opts.resumeSessionId)
   }
-  return spawnClaudeStreamed(opts.prompt, opts.cwd, timeoutMs, opts.images!, opts.profilePath, opts.bare)
+  return spawnClaudeStreamed(opts.prompt, opts.cwd, timeoutMs, opts.images!, opts.profilePath, opts.bare, opts.resumeSessionId)
 }
 
 function spawnClaudeText(
@@ -250,11 +252,13 @@ function spawnClaudeText(
   timeoutMs: number,
   profilePath?: string,
   bare?: boolean,
+  resumeSessionId?: string,
 ): Promise<ClaudeResult> {
   const args = [
     ...(bare ? ['--bare'] : []),
     '--dangerously-skip-permissions',
     ...(profilePath ? ['--settings', profilePath] : []),
+    ...(resumeSessionId ? ['--resume', resumeSessionId] : []),
     '-p',
     prompt,
     '--output-format',
@@ -361,6 +365,7 @@ function spawnClaudeStreamed(
   images: ClaudeImage[],
   profilePath?: string,
   bare?: boolean,
+  resumeSessionId?: string,
 ): Promise<ClaudeResult> {
   // Local Claude Code v2.1.143 enforces that --input-format=stream-json must
   // be paired with --output-format=stream-json (the friendlier `--output-format
@@ -370,6 +375,7 @@ function spawnClaudeStreamed(
     ...(bare ? ['--bare'] : []),
     '--dangerously-skip-permissions',
     ...(profilePath ? ['--settings', profilePath] : []),
+    ...(resumeSessionId ? ['--resume', resumeSessionId] : []),
     '-p',
     '--input-format',
     'stream-json',