Middle-click paste fires twice (on mousedown and mouseup) in VS Code integrated terminal — regression in 2.1.175

Environment:

• Claude Code version: 2.1.175 (regression — 2.1.173 was fine)
• OS: Ubuntu 24.04.4 LTS, kernel 6.14.0-24-generic, X11 session
• Terminal: VS Code 1.123.2 (snap) integrated terminal, TERM=xterm-256color
• Shell: bash

Description:
After Claude Code auto-updated from 2.1.173 to 2.1.175 (06:20 UTC), middle-mouse-button paste (X11 PRIMARY selection) inside Claude Code's prompt now inserts the clipboard content twice — once on the middle-button press event and again on the release event. This does not happen in a plain shell or other programs in the same VS Code terminal — only within Claude Code's TUI. Reverting to the 2.1.173 binary resolves the issue.

Steps to reproduce:

1. Select some text elsewhere to populate the X11 PRIMARY selection.
2. In VS Code's integrated terminal, run claude (v2.1.175).
3. Middle-click in the prompt input.
4. Observe the selected text is pasted twice in a row.

Expected: Text is pasted once.