/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_

从 /resume session picker 的入口点开始，并比较在 xterm 中运行 Copilot 时它的选择渲染与 trust prompt picker 的选择渲染。完成标准是：选中的 session 使用与 trust prompt 相同的反转视频样式进行明显高亮，并且使用箭头键导航时能够清楚地看出当前选择。

由索引模型根据 Issue 内容生成。