Fix CRLF handling in display-only terminals (#39538)

## Before

<img width="558" height="739" alt="Screenshot 2025-10-03 at 11 08 43 PM"
src="https://github.com/user-attachments/assets/5dae7f9d-03b6-48eb-826d-e2be60320546"
/>

## After

<img width="551" height="843" alt="Screenshot 2025-10-04 at 8 29 51 PM"
src="https://github.com/user-attachments/assets/2b06dcec-7758-42ad-acf0-c32a7f50f1b1"
/>

No release notes because we aren't using display-only terminals anywhere
yet (`codex-acp` will be the first to use them, and it's still
feature-flagged right now).

Release Notes:

- N/A
bcd2d269e2Richard Feldman committed on 10/5/2025, 2:43:46 AM· committed by GitHubparentb32075c
1 file changedLine totals unavailable