Mouse scroll in tmux scrolls input box instead of output

Description

When running Claude Code inside a tmux session, using the mouse wheel to scroll scrolls the input box instead of the output/conversation area. This makes it very difficult to review previous responses or conversation history.

Expected Behavior

Mouse scroll should scroll the output/conversation area, allowing users to review previous messages and responses.

Actual Behavior

Mouse scroll scrolls the input box (where you type), which is not useful as the input is typically short.

Environment

• Claude Code running in tmux
• Multiple tmux sessions with Claude Code instances
• Linux terminal environment

Impact

This significantly degrades usability when working in tmux sessions, as reviewing conversation history requires keyboard navigation instead of the more natural mouse scrolling.

Workaround

Currently need to use keyboard shortcuts to navigate output, which is less convenient than mouse scrolling.