[BUG] v2.1.172 regression: scroll wheel sends arrow keys in WSL2 terminal (Using Ubuntu)

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 Description

Starting from version 2.1.172, the mouse scroll wheel no longer scrolls the TUI — instead it sends arrow key escape sequences, navigating through conversation history one line at a time. The TUI itself
displays the message: Scroll wheel is sending arrow keys · use PgUp/PgDn to scroll.

Rolling back to 2.1.170 restores correct scroll behavior.

## Environment

• Claude Code version: 2.1.172 (regression), 2.1.170 (working)
• OS: Windows 11 + WSL2 (Ubuntu)
• Kernel: Linux 6.6.87.2-microsoft-standard-WSL2
• Terminal: (WSL2 default terminal)

## Steps to Reproduce

1. Install or update to Claude Code 2.1.172
2. Launch claude in a WSL2 terminal
3. Attempt to scroll up/down with the mouse scroll wheel

## Expected Behavior

Mouse scroll wheel scrolls the TUI viewport up/down.

## Actual Behavior

Scroll wheel sends arrow key sequences instead of scroll events. TUI shows the hint: Scroll wheel is sending arrow keys · use PgUp/PgDn to scroll.

## Workaround

Roll back to 2.1.170:
```bash
ln -sf ~/.local/share/claude/versions/2.1.170 ~/.local/bin/claude

Related Issues

• #67289 (different symptom: tmux scrollback broken in alternate-screen mode, also introduced in 2.1.172)

What Should Happen?

roll back into v2.1.170

Error Messages/Logs

Scroll wheel is sending arrow keys · use PgUp/PgDn to scroll

Steps to Reproduce

roll back into v2.1.170

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

2.1.170

Claude Code Version

2.1.172

Platform

Anthropic API

Operating System

Ubuntu/Debian Linux

Terminal/Shell

WSL (Windows Subsystem for Linux)

Additional Information

_No response_