skills warnings and errors distort the /skills menu

### Describe the bug

if a lot of skills have warnings or errors and you use `/skills` the menu for skills is not visible. The skills can't be scrolled into view. The terminal needs to be expanded in order to see the skills.

expanding the window shows skills

### Affected version

GitHub Copilot CLI 0.0.420

### Steps to reproduce the behavior

load skills that have errors and warnings
reduce the height of the terminal window
use `/skills`
see that the warnings and errors are visible but the actual skills are only visible if you expand the terminal height

### Expected behavior

the menu warnings and errors don't prevent the `/skills` menu from being displayed. The info is visible without having to force the height,

### Additional context

_No response_

Reproduce the issue by loading skills with warnings and errors, shrinking the terminal, and running `/skills`. Start by locating the `/skills` menu rendering and its warning/error display; done means the skills remain visible and usable without expanding the terminal.

Written by the indexing model from the issue text.