🐛 fix(vscode): 删 worktree 前扫 /proc 检测进程占用，命中则中止清理

dev server 常驻在 worktree 里持续写构建产物，递归删除与写入竞态导致
rmdir 撞 ENOTEMPTY。新增 findProcessesUsingWorktree 扫 /proc 找 cwd 或
fd 落在 worktree 下的进程，三处删除调用点（拖到完成列 / 手动删 / 删整工单）
命中即弹错误 toast 列出 pid+命令并中止（不删、不杀进程），用户停掉后重试。
非 Linux 无 /proc 返回空，降级为原直接删除。

vscode/src/git/worktree.test.ts

@@ -0,0 +1,37 @@
+import { spawn } from 'node:child_process'
+import { existsSync, mkdtempSync, rmSync } from 'node:fs'
+import * as os from 'node:os'
+import * as path from 'node:path'
+import { describe, expect, it } from 'vitest'
+import { findProcessesUsingWorktree } from './worktree'
+
+// 检测靠扫 /proc，只有 Linux 有；别的平台整组跳过（函数本身也会返回空）。
+describe.runIf(existsSync('/proc'))('findProcessesUsingWorktree', () => {
+  it('抓到 cwd 落在 worktree 目录下的常驻进程', async () => {
+    const dir = mkdtempSync(path.join(os.tmpdir(), 'wt-proc-'))
+    // cwd 设进 dir 的 sleep，模拟仍在 worktree 里跑的 dev server
+    const child = spawn('sleep', ['30'], { cwd: dir, stdio: 'ignore' })
+    try {
+      await new Promise<void>((resolve, reject) => {
+        child.on('spawn', () => resolve())
+        child.on('error', reject)
+      })
+      const hits = findProcessesUsingWorktree(dir)
+      expect(hits.some(h => h.pid === String(child.pid))).toBe(true)
+    }
+    finally {
+      child.kill('SIGKILL')
+      rmSync(dir, { recursive: true, force: true })
+    }
+  })
+
+  it('没进程占用的目录返回空数组', () => {
+    const dir = mkdtempSync(path.join(os.tmpdir(), 'wt-empty-'))
+    try {
+      expect(findProcessesUsingWorktree(dir)).toEqual([])
+    }
+    finally {
+      rmSync(dir, { recursive: true, force: true })
+    }
+  })
+})