[BUG] Text doesn't reflow when terminal is resized from narrower to wider

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?

Bug Report

Problem:
When resizing an iTerm2 pane from narrower to wider, existing Claude Code text doesn't reflow to take advantage of the additional width, leaving unnecessary line breaks.

Steps to Reproduce:

1. Start Claude Code session in iTerm2
2. Make the terminal pane narrow
3. Have conversation with longer responses (text will wrap to narrow width)
4. Resize pane to be wider
5. Scroll up to view previous responses

Expected Behavior:
Text should reflow to use the available wider space, removing unnecessary line breaks

Actual Behavior:

• Text remains wrapped at the original narrow width
• Lots of whitespace on the right side
• Short lines that could be combined into longer ones
• Text looks cramped despite having more space

Note:

• Resizing from wider to narrower works correctly (text wraps properly)
• Only expanding width causes the reflow issue
• New responses after resize format correctly for the new width

Environment:

• Platform: macOS
• Terminal: iTerm2
• Claude Code version: [current version]

What Should Happen?

Text should reflow to use the available wider space, removing unnecessary line breaks

Error Messages/Logs

Steps to Reproduce

1. Start Claude Code session in iTerm2
2. Make the terminal pane narrow
3. Have conversation with longer responses (text will wrap to narrow width)
4. Resize pane to be wider
5. Scroll up to view previous responses

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

1.0.128 (Claude Code)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

iTerm2

Additional Information

_No response_