ui: render all nav stack widgets

either set_visible on the lower ones, and call show_event/hide_event from set_visible generically, or only update state of lower ones

Start by tracing the nav stack widgets and the existing set_visible, show_event, and hide_event behavior. Determine whether lower widgets should be made visible or only have their state updated; done means all nav stack widgets render correctly with consistent visibility and event handling.

Written by the indexing model from the issue text.