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

在 mintty 中使用 cmd 或 Git Bash，而不是 Windows Terminal，复现 Copilot CLI 1.0.79-5 的问题，并观察终端标题数秒。从 CLI 启动开始跟踪终端标题的处理；当标题保持为 "GitHub Copilot" 而不是变为 "Windows PowerShell" 时，即表示完成。