restorePoiBottomSheetAfterOverlay

R74.4: inverse of showFragmentInBottomSheet for the entity-detail overlay flow. When the user opens an overlay like the Working Hours dialog from a POI's "View All", showFragmentInBottomSheet hides poiBottomSheet (the entity-detail card) and expands defaultBottomSheet (the overlay host). Closing the overlay (X button, swipe, system back) must therefore restore those two states so the user returns to the entity-detail card — NOT the clean map — when a POI is still selected. Called from onDestroyView so every close path (X tap + system back + parent navigation) routes through it. No-op when the POI fragment isn't in the back-stack (i.e. the overlay was opened in a different context), so this is safe to call unconditionally.