sculpt: consider screen pos for pointer tracking

When inferring the global pointer position from input events referring
to the leitzentrale, we must take the leitzentrale's panorama position
into account. Otherwise, the hovered display cannot always be reliably
determined.

Issue #5370

repos/gems/src/app/sculpt_manager/main.cc

@@ -950,7 +950,7 @@ struct Sculpt::Main : Input_event_handler,
 	void handle_input_event(Input::Event const &ev) override
 	{
 		ev.handle_absolute_motion([&] (int x, int y) {
-			_pointer_pos.construct(x, y); });
+			_pointer_pos.construct(x + _screen_pos.x, y + _screen_pos.y); });
 
 		Keyboard_focus_guard focus_guard { *this };