Deleting worktree fails w/out recovery

When deleting a worktree as part of session delete it failed to delete because, I think, I had PS open to the worktree (Windows). Ideally it would force delete anyway but at least it should let me try again. I just showed this error.

Which stayed for a minute or something then disappeared.

I just saw it appear again so maybe there is some timer running to try again - I've closed consoles... maybe a detached web app or something is running.

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Delete failed
Failed to delete session: The process cannot access the file because it is being used by another process. (os error 32)
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It would be nice if the error mentioned what file / directory was being deleted. Maybe have a "try again" button or some info saying "this will be retried again every minute forever".

首先，在 worktree 中打开 PowerShell 窗口的情况下重现 Windows 上的会话删除，然后观察显示的失败以及是否会重试。跟踪 session-delete-worktree 的 worktree 清理流程；done 应提供可恢复的重试或明确的重试行为，并确定失败涉及的文件或目录。

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