(feat) Resume Screen Selection: Highlight selected row for better visibility

What variant of Codex are you using?

CLI

What feature would you like to see?

In codex resume, make the currently selected session row easier to track by using the same selected-row highlight treatment already used in other Codex TUI pickers. Really small/niche QoL issue that's been irking me lately

Builds on #16420, but is narrower: reuse the existing selection styling pattern rather than introducing a new resume-picker-specific UI.

Additional information

Small proof of concept showing the same (sanitized) session list before and after the change:

Current:

<img width="1788" height="1076" alt="Image" src="https://github.com/user-attachments/assets/213d5eed-c3b3-4968-b1d9-3305d9848da0" />

After (using same styling as other TUI pickers):

<img width="1786" height="1076" alt="Image" src="https://github.com/user-attachments/assets/10d94ccf-6b5d-49e0-b88c-9b4409ab2613" />

Alternate (tried a stronger full-row background version, more visually obvious idk)

<img width="1796" height="1090" alt="Image" src="https://github.com/user-attachments/assets/0a5007c4-379a-4f39-a55d-5f2317e6de72" />

idt the team's taking public PRs anymore, though i can give more implementation details... but i mean it's like a 10 line diff anyway 😭

• File touched: codex-rs/tui/src/resume_picker.rs
• Applies the selected-row style to the visible spans in the selected resume row
• Uses the existing cyan + bold selected-state treatment
• Adds a test assertion that visible cells in the selected row use the selected foreground styling

Local checks run:

• just fmt
• cargo test -p codex-tui resume_table_snapshot
• cargo test -p codex-tui