Feature Request: Slash Command `cwd` supports '/' to show matching directories in Windows

### Describe the feature or problem you'd like to solve

_No response_

### Proposed solution

When Copilot-CLI executes the slash command `cwd`, ​​it lists all matching directories below, but only supports backslashes ('\').

In Windows CLI environments, changing the working directory usually involves commands like `cd ..\..`, but typing backslashes ('\') is always more cumbersome than forward slashes ('/') (because the right hand needs to move further).

So Powershell and cmd support forward slashes ('/') instead of backslashes ('\').
It would be great if Copilot-CLI could also support this.

### Example prompts or workflows

_No response_

### Additional context

GitHub Copilot-CLI: v0.0.389
OS: Windows 11 25H2