UX on Nav

Since there's a delay on nav rollover, it's tempting to click on the nav item, which also closes the nav.

Start by reproducing the delayed nav rollover and the click behavior described in the issue. Trace the navigation entry point and determine which interaction closes the nav; done should mean users can interact with a nav item without the rollover delay making the menu close unexpectedly.

Written by the indexing model from the issue text.