Codex: the mouse wheel moves the selection in menus such as "Implement this plan?" #696

What happens

In a Codex session, when Codex shows a selection menu (for example "Implement this plan?" after a plan turn), scrolling the mouse wheel over the pane moves the menu's selection instead of scrolling. One notch down moves the selection from "Yes, implement this plan" to "No, stay in Plan mode", and one notch up moves it back to "Yes, implement this plan", which is one Enter from starting the implementation. PageUp and PageDown do the same thing (Codex binds them to the selection there), so neither the wheel nor the page keys scroll the transcript behind the menu.

Why

codex-cli does not enable mouse tracking in these versions, so Codeman scrolls a Codex pane by turning the wheel into PageUp and PageDown (_maybePageCliTranscript). In the composer that pages the transcript. In a Codex selection menu the same keys move the selection. Codeman already stops doing this while a pending approval is showing (tabAlerts action), but the "Implement this plan?" prompt, the /model, /permissions and /review pickers are deliberately not blocked dialogs (test/codex-blocked-detection.test.ts), so nothing stops the wheel there.

Measured

• codex-cli 0.162.1 and 0.164.0, run under tmux: alternate_on=1, mouse_any_flag=0 in the empty composer, in plan mode and at the plan prompt, with or without -c tui.alternate_screen="always", tui.fullscreen_transcript=true or tui.mouse_scroll_speed=2.0.
• At the "Implement this plan?" prompt (tmux send-keys): PageDown moved the selection from option 1 to option 3, PageUp moved it to option 1, Up and Down moved it one option. Ctrl+T and Ctrl+B changed nothing.
• Through Codeman 1.43.0 and master in Chromium (wheel events over the pane): one notch down put the selection on option 3, one notch up put it on option 1.
• The 0.163.0 and 0.164.0 release notes do not mention scrolling, the mouse or plan prompts.

Expected

The wheel does not move a Codex menu's selection. The transcript behind the menu cannot be scrolled with keys in Codex's menu, so the wheel should simply be ignored there and page the transcript again once the menu closes.

Fix

Fix: #698. The related wheel problem on the same panes, where a mouse needs several notches before anything moves, is #697 (fix: #699).