cmd+click open links twice

### Describe the bug

I have developed the habbit of cmd+click to open links from a VS Code terminal on mac because the default behavior of links in the terminal output is that
- click does nothing
- cmd+click opens it in the browser

For Copilot CLI, the behavior is different:
- click opens the link in the browser - this is different from VS Code but it's good
- cmd+click opens the link twice in the browser - not expected

### Affected version

1.0.56

### Steps to reproduce the behavior

1. Ask Copilot CLI to echo a link in a VS Code terminal
2. click the link
3. cmd+click the link

Like what this screenshot indicates

### Expected behavior

I expect the link to be opened only once.

### Additional context

_No response_

Reproduce the issue in a VS Code terminal using Copilot CLI 1.0.56, following the listed click and cmd+click steps. Trace the CLI's terminal link and modifier-key handling; done means a cmd+click opens the link exactly once while ordinary clicking still opens it once.

由索引模型根据 Issue 内容生成。