Add vim-style navigation for CLI option selection (#7784)

## Summary

Support "j" and "k" keys as aliases for "down" and "up" so vim users
feel loved. Only support these keys when the selection is not
searchable.

## Testing
- env -u NO_COLOR TERM=xterm-256color cargo test -p codex-tui


------
[Codex
Task](https://chatgpt.com/codex/tasks/task_i_693771b53bc8833088669060dfac2083)

codex-rs/tui/src/bottom_pane/list_selection_view.rs

@@ -284,6 +284,11 @@ impl BottomPaneView for ListSelectionView {
                 modifiers: KeyModifiers::NONE,
                 ..
             } /* ^P */ => self.move_up(),
+            KeyEvent {
+                code: KeyCode::Char('k'),
+                modifiers: KeyModifiers::NONE,
+                ..
+            } if !self.is_searchable => self.move_up(),
             KeyEvent {
                 code: KeyCode::Down,
                 ..
@@ -298,6 +303,11 @@ impl BottomPaneView for ListSelectionView {
                 modifiers: KeyModifiers::NONE,
                 ..
             } /* ^N */ => self.move_down(),
+            KeyEvent {
+                code: KeyCode::Char('j'),
+                modifiers: KeyModifiers::NONE,
+                ..
+            } if !self.is_searchable => self.move_down(),
             KeyEvent {
                 code: KeyCode::Backspace,
                 ..