Bug: Cmd+V paste doesn't work in iTerm2

### Describe the bug

Paste via Cmd+V does not work in Copilot CLI when running in iTerm2 on macOS. The only way to paste is via the menu bar (Edit → Paste).

For comparison, Claude Code CLI handles paste correctly in the same terminal with identical settings.

Tried without success:

• /terminal-setup command
• Cmd+Shift+V
• iTerm bracketed paste mode enabled

Environment:

• macOS, iTerm2
• Copilot CLI v1.0.75

Expected: Cmd+V should paste text into the input
Actual: Nothing happens

### Affected version

GitHub Copilot CLI 1.0.75.

### Steps to reproduce the behavior

_No response_

### Expected behavior

_No response_

### Additional context

_No response_

在 macOS 的 iTerm2 中使用 Copilot CLI v1.0.75 重现该问题，检查 Cmd+V 以及报告中描述的已尝试终端设置选项。将其行为与通过菜单栏粘贴进行比较，并在 Cmd+V 能够将文本粘贴到 CLI 输入中时确认工作已完成。

由索引模型根据 Issue 内容生成。