Codex session disconnects during long-running/high-output commands on Windows PowerShell (aborted / Unknown process id)

Summary

When running longer test commands in Codex on Windows + PowerShell, the session frequently drops and becomes unusable.

• OS: Windows
• Shell: PowerShell
• Project type: Python (uv + pytest)

## Steps to Reproduce

1. Run:

```bash
uv run pytest -v

1. Or run medium/large test batches (multiple tests/*.py files).
2. Wait during execution and continue polling output.

## Actual Behavior

• Session terminates unexpectedly.
• Errors include:
• aborted
• write_stdin failed: Unknown process id <id>
• In some runs, output log files are 0 bytes (suggesting interruption before command fully starts).
• This happened repeatedly (at least 4 times in one session).

## Expected Behavior

• Session remains stable for long-running/high-output commands.
• If session transport fails, background process control and exit-code retrieval should still be reliable.

## Temporary Workaround (works)

• Use detached background execution + log polling (instead of streaming large output directly).
• Start pytest in background, then poll status/log tail with short commands.
• This reliably completed the same batch (example: 31 passed).

## Impact

• Long test/verification workflows are unreliable.
• Requires custom scripts and manual polling.
• Reduces development productivity.