/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_

從 /resume session picker 的進入點開始，並比較在 xterm 中執行 Copilot 時它的選取呈現與 trust prompt picker 的選取呈現。完成標準是：選取的 session 使用與 trust prompt 相同的反轉影像樣式明顯醒目顯示，且使用方向鍵導覽時能清楚看出目前的選取項目。

由索引模型根據 Issue 內容生成。