[BUG] ExitPlanMode "Other" input truncates with … while typing, but wraps correctly when content returns from $EDITOR

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

The custom text field in AskUserQuestion's "Other" branch (and the feedback input on ExitPlanMode's shift+tab flow) behaves differently depending on how you get content into it.
If you type past the visible width, the field clips with a trailing … and everything after that point disappears from view. If you instead open $EDITOR via ctrl+g, write the same content there, save, and close, the dialog renders it as a soft-wrapped multi-line block. The renderer clearly knows how to wrap that buffer. It just doesn't during live typing.

What Should Happen?

The custom input field should wrap text as you type, matching how the same content renders after an $EDITOR round-trip. At minimum, once the field overflows, a visible hint like "press ctrl+g to edit" should appear so it's clear the content isn't lost.

Error Messages/Logs

Steps to Reproduce

1. From any session, trigger an AskUserQuestion with an "Other" branch.
2. Tab or arrow to the custom input row (option 4 in the default layout).
3. Type past the visible width. Text clips with … — nothing past that point is visible.
4. Press ctrl+g, write the same text in $EDITOR, save and close.
5. The same content now wraps across multiple rows in the dialog.

Claude Model

None

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.144 (Claude Code)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Other

Additional Information

<img width="1662" height="1822" alt="Image" src="https://github.com/user-attachments/assets/6bbdd3dc-308c-4b33-94f5-d823eb4ccb23" />