/resume session picker has invisible selection highlighting (trust prompt picker works fine)

### Describe the bug

The /resume session picker has nearly invisible selection highlighting, while the "Do you trust the files in this folder?" picker in the SAME terminal renders with clear reverse-video highlighting. This proves the terminal supports proper highlighting - the /resume picker just doesn't use it. Please apply ┃
the same reverse-video style used in the trust prompt to the /resume session picker.

### Affected version

GitHub Copilot CLI 1.0.70

### Steps to reproduce the behavior

Open xterm
run copilot
/resume
Attempt to use arrow keys to select session, unable to see which session is being selected.

### Expected behavior

_No response_

### Additional context

_No response_

Start with the /resume session picker entry point and compare its selection rendering with the trust prompt picker when running Copilot in xterm. Done means the selected session is visibly highlighted with the same reverse-video style used by the trust prompt, and arrow-key navigation makes the selection clear.

Written by the indexing model from the issue text.