[BUG] Message suggestions being sent when switching between agents with shift-<up/down>-enter

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?

Suggested messages in Claude Code CLI (running on Ghostty) are being sent when pressing "enter" key when I am switching between teammates.

I can indeed change between teammates using <shift>-<up/down>-<enter> but it also sends the current suggestion as a message.

<img width="850" height="563" alt="Image" src="https://github.com/user-attachments/assets/b4ca7f81-8762-4dce-9df4-7d52cd223121" />

What Should Happen?

Expected behavior:
I can press <shift>-<up/down>-<enter> to switch agents, without message suggestions in the input being fired.

Error Messages/Logs

Steps to Reproduce

1. Create an agent team
2. Use <shift>-<up/down>-<enter> to switch between agents
3. Observe input suggestions being sent on <enter>

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.39

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Other

Additional Information

_No response_