[BUG] Terminal resize causes content duplication and display corruption on macOS

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?

When resizing the terminal window (dragging edges to change width or height), the display becomes corrupted:

• Content gets duplicated / repeated multiple times
• The UI does not cleanly redraw to fit the new dimensions
• The issue persists until pressing Ctrl+L or restarting Claude Code
• Happens on every terminal window, not specific to any one session

The root cause appears to be that the TUI renderer does not properly clear previous frames on SIGWINCH before redrawing, pushing
duplicate content into the scrollback buffer.

What Should Happen?

On resize, Claude Code should clear the current frame and redraw cleanly to fit the new terminal dimensions — showing exactly one instance of the interface, no duplication or overlapping.

Error Messages/Logs

Steps to Reproduce

1. Start claude in any terminal
2. Have some conversation content on screen
3. Resize the terminal window by dragging the edge
4. Content duplicates, display becomes garbled

Note: The issue does NOT occur in fullscreen mode — only when the window is in a smaller/windowed state.

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

v2.1.133

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_