Copilot CLI changes terminal title to "Windows PowerShell" when not launched in Windows Terminal

Describe the bug

When launched in a terminal that is not in Windows Terminal, Copilot CLI first set the terminal title to "GitHub Copilot", but it always automatically becomes "Windows PowerShell" after a second or two

Affected version

1.0.79-5

Steps to reproduce the behavior

1. Open a terminal in a host that's not Windows terminal, like cmd in Windows native conhost or Git Bash in mintty
2. Launch Copilot CLI
3. Observe the title change

Expected behavior

The title should stay "GitHub Copilot" and not change to "Windows PowerShell"

Additional context

No response

Windows Terminal ではなく、mintty 上の cmd または Git Bash で Copilot CLI 1.0.79-5 の問題を再現し、数秒間にわたってターミナルタイトルを観察します。CLI の起動時からターミナルタイトルの処理を追跡します。タイトルが "Windows PowerShell" に変わらず、"GitHub Copilot" のままであれば完了です。