[BUG] /terminal-setup to enable shift+enter does not work in CMD or Powershell

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?

/terminal-setup to enable shift+enter does not work in CMD or Powershell
When I try, it just tells me to be sure and run Windows Terminal-- and I am. Then Claude tells me it's a but and to file it here-- and that's what I'm doing.

What Should Happen?

Shift+Enter should be able to create a new line.

Error Messages/Logs

Terminal setup cannot be run from windows-terminal.

     This command configures a convenient Shift+Enter shortcut for multi-line prompts.
     Note: You can already use backslash (\) + return to add newlines.

     To set up the shortcut (optional):
     1. Exit tmux/screen temporarily
     2. Run /terminal-setup directly in one of these terminals:
        • Windows: Windows Terminal
        • IDE: VSCode, Cursor, Windsurf
        • Other: Ghostty, WezTerm
     3. Return to tmux/screen - settings will persist

Steps to Reproduce

Terminal setup cannot be run from windows-terminal.

This command configures a convenient Shift+Enter shortcut for multi-line prompts.
Note: You can already use backslash (\) + return to add newlines.

To set up the shortcut (optional):

1. Exit tmux/screen temporarily
2. Run /terminal-setup directly in one of these terminals:

• Windows: Windows Terminal
• IDE: VSCode, Cursor, Windsurf
• Other: Ghostty, WezTerm

1. Return to tmux/screen - settings will persist

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.0.45 (Claude Code)

Platform

Other

Operating System

Windows

Terminal/Shell

PowerShell

Additional Information

_No response_