Codex CLI v0.120.0 fails to resume old sessions: Unknown parameter 'prompt_cache_retention'

Summary

Resuming an older Codex session consistently fails with a remote compact error.

Environment

• Codex CLI: 0.120.0
• OS: macOS
• Model: gpt-5.4
• Session ID: 019d6fa0-db65-7f83-9531-35df54674d76

Exact repro

```bash
codex resume 019d6fa0-db65-7f83-9531-35df54674d76 "ping" --no-alt-screen

I also tried:

codex resume 019d6fa0-db65-7f83-9531-35df54674d76 "ping" --no-alt-screen --disable enable_request_compression

Actual result

Codex fails with:

Error running remote compact task: {
"error": {
"message": "Unknown parameter: 'prompt_cache_retention'.",
"type": "invalid_request_error",
"param": "prompt_cache_retention",
"code": "unknown_parameter"
}
}

Expected result

The session should resume normally, or compact successfully without sending unsupported parameters.

Notes

• I could reproduce this directly from the CLI.
• The failure appears tied to remote compaction of a large old session.
• I did not find prompt_cache_retention in my local editable Codex config.