Windows cached task hangs after first compound command when stdio pipe remains open

先从缓存执行路径及其对 Windows 子进程 stdout/stderr 管道的处理入手，然后使用链接的复现仓库重现组合命令，并将其与使用 --no-cache 的运行进行比较。完成的标准是：第一个子进程退出后，缓存的 Windows 运行会继续执行第二个命令，且不会留下孤立的 vctip 进程。

Summary

On Windows, a cached vp run task can hang after the first command in a compound script has completed, before the next && command starts.

This was reproduced with a script shape similar to:

{
  "scripts": {
    "test": "cargo test -p ox_mf2_parser --all-targets --color always && vp test"
  }
}

Reproduction

Repro repo: https://github.com/kazupon/vite-task-windows-issue-1
(cause repo: https://github.com/intlify/intlify)

In GitHub Actions, the normal cached Windows run hangs, while the Windows --no-cache control run completes successfully.

Observed behavior

The cached run prints and completes the cargo test output, but never prints or starts the following $ vp test command.

Process snapshots show only the vpr / vp / node runner process tree remaining. No cargo, rustc, or vitest process remains. At workflow cleanup, GitHub Actions reports an orphaned vctip process.

Expected behavior

After the direct child process for the first command exits, the runner should observe completion and continue to the next && command, even if a descendant temporarily keeps stdout/stderr handles open.

Suspected cause

The cached execution path drains piped stdout/stderr before awaiting the direct child process. On Windows, if a descendant keeps an inherited pipe handle open, EOF never arrives, so the runner never reaches child wait or Windows Job Object cleanup.