Debug logs saved to location is missing a `\`.

### Describe the bug

When outputting debug logs, the folder location is missing a `\`. This will result an error if you try and copy/paste this path into Windows Explorer.

### Affected version

1.0.62

### Steps to reproduce the behavior

1. type `/collect-debug-logs file` in the command box of copilot.
2. Press Enter and select a chat you want to export.
3. Wait until you get the message that the "Debug logs saved to:"
4. Copy and paste that path into file explorer, you will receive a "C:\users\.copilot\ is unavailable" error message.

### Expected behavior

I can copy the path from copilot cli output into Windows Explorer or Run dialog box and the file/directory opens.

### Additional context

OS: Windows 11 25H2
Terminal: Windows Terminal 1.24.11321.0
Copilot CLI: 1.0.62

从命令入口 `/collect-debug-logs file` 开始，跟踪 Windows 路径为 `Debug logs saved to:` 消息进行格式化的位置。在 Windows 上复现该命令，然后验证将报告的路径复制到文件资源管理器或“运行”对话框中可以打开导出的日志。

由索引模型根据 Issue 内容生成。