- Fix `child_process` shell command translation to handle shell
redirections (`1>&-`, `< file`), piped commands (`cmd1 | cmd2`), and
shell variable prefixes (`"$NODE"`, `${NODE}`). Previously shell
operators were passed to the CLI arg translator, causing parse failures
or incorrect output.
- Remove duplicate `transformDenoShellCommand` call from
`normalizeSpawnArguments` — it was already called in `buildCommand`, and
the double transformation corrupted POSIX `'\''` quoting.
- Add `wrap_eval` parameter to `op_node_translate_cli_args` so shell
command contexts skip eval code wrapping (which introduces
metacharacters unsafe for shell embedding).
- Map `BrokenPipe` to `EPIPE` (was incorrectly mapped to `EBADF`) in
`stream_wrap`, and catch `BrokenPipe` in `process.stdout`/
`process.stderr` `writeSync` to emit it as an async error event.
- Add minimal `_handle` with `ref()`/`unref()`/`close()` to PIPE stdin.
Intentionally omits `readStart`/`readStop`/`reading` — adding those
resets `_readableState.reading`, which triggers duplicate `_read()`
calls with orphaned reffed promises that prevent process exit.
- Ref `io.stdin` in `_read()` and unref on pause when no `readStop`
exists, matching Node.js event loop ref-counting behavior.
- Add platform-specific quoting in `transformDenoShellCommand`: POSIX
uses single quotes with `'\''` escaping, Windows uses double quotes with
`\\` doubling before `"`.
- Add Windows `cmd.exe` detection (`/d /s /c` pattern) in `buildCommand`
for shell command transformation.
- Deduplicate `--unstable-*` flags in `fork()` between CLI translator
and bootstrap args.

Enables 3 new node_compat tests:
  - `test-stdio-closed.js`
  - `test-stdout-close-catch.js`
  - `test-stdout-close-unref.js`


Needs: 
- [x] #32086
- [x] #32087