Function cleanupStaleAgentWorktrees

src/utils/worktree.ts:1060–1138

(
  cutoffDate: Date,
)

 * dir), it's left in place — a later readdir finding it stale again is harmless.
 */
export async function cleanupStaleAgentWorktrees(
  cutoffDate: Date,
): Promise<number> {
  const gitRoot = findCanonicalGitRoot(getCwd())
  if (!gitRoot) {
    return 0
  }

  const dir = worktreesDir(gitRoot)
  let entries: string[]
  try {
    entries = await readdir(dir)
  } catch {
    return 0
  }

  const cutoffMs = cutoffDate.getTime()
  const currentPath = currentWorktreeSession?.worktreePath
  let removed = 0

  for (const slug of entries) {
    if (!EPHEMERAL_WORKTREE_PATTERNS.some(p => p.test(slug))) {
      continue
    }

    const worktreePath = join(dir, slug)
    if (currentPath === worktreePath) {
      continue
    }

    let mtimeMs: number
    try {
      mtimeMs = (await stat(worktreePath)).mtimeMs
    } catch {
      continue
    }
    if (mtimeMs >= cutoffMs) {
      continue
    }

    // Both checks must succeed with empty output. Non-zero exit (corrupted
    // worktree, git not recognizing it, etc.) means skip — we don't know
    // what's in there.
    const [status, unpushed] = await Promise.all([
      execFileNoThrowWithCwd(
        gitExe(),
        ['--no-optional-locks', 'status', '--porcelain', '-uno'],
        { cwd: worktreePath },
      ),
      execFileNoThrowWithCwd(
        gitExe(),
        ['rev-list', '--max-count=1', 'HEAD', '--not', '--remotes'],
        { cwd: worktreePath },
      ),
    ])
    if (status.code !== 0 || status.stdout.trim().length > 0) {
      continue
    }