tui.select.pageUp/pageDown were configurable but ignored by SelectList,
SettingsList, editor autocomplete, and most coding-agent selectors. In
fullscreen mode, the default PageUp/PageDown also scrolled the transcript
instead of reaching the focused list.
- add getSelectPageIndex() and handle page keys in SelectList, SettingsList,
editor autocomplete, and the model, scoped models, auth, user message,
settings submenu, llama search, and /mcp selectors
- add Component.capturesViewportInput: a focused component that sets it
receives fullscreen viewport keys instead of the transcript, as a focused
overlay already does
- let page keys move an open autocomplete menu before app actions, so a
remapped Ctrl+V pages the menu instead of pasting an image
closes#7629
Co-authored-by: muyiyr <940955635@qq.com>
