Migrate fullscreen overlay selectors onto routeSgrMouseInput() and
routeSelectListMouse(), removing duplicated SGR parsing and SelectList
hit-test boilerplate. Behavior-preserving: wheel step sizes, footer/row
offset guards, and consumption semantics are unchanged.
Make the inline-picker wrappers (theme/thinking/queue-mode/show-images/
plugin) MouseRoutable, each subtracting their single top-border row before
delegating to SelectList.routeMouse(). Name previously magic coordinate
offsets (spacerRowsAfterTabs, contentColInset).
Wolfgang Schoenberger
3995e629ea