Can not authorize MCP server using Oauth

### Describe the bug

I'm trying to add sentry MCP server to copilot but it stuck on authentication step.

### Affected version

GitHub Copilot CLI 1.0.49

### Steps to reproduce the behavior

1. Add sentry MCP server to ~/.copilot/mcp-config.json
```
"sentry": {
"url": "https://mcp.sentry.dev/mcp"
}
```
2. start copilot cli and run `/mcp auth sentry`

### Expected behavior

It shows a url to open and authorize on the web

### Actual result

It show this and stuck until timed out

```
Authenticating: sentry

◎ Waiting for authorization in browser...
```

### Additional context

The CLI is running on a remove server and I accessed via SSH, so opening in a browser should not be expected

从入口 `/mcp auth sentry` 和 `~/.copilot/mcp-config.json` 中显示的 MCP 配置开始。使用 Sentry 服务器 URL 通过 SSH 重现该流程，然后跟踪等待浏览器授权的位置。当远程用户无需在 CLI 主机上使用浏览器即可完成或继续 OAuth 时，即表示完成。

由索引模型根据 Issue 内容生成。