PolygonOverlayItem
A polygon overlay primitive used to plot a "do-not-enter" / restricted-area overlay onto the map without affecting entity selection or routing layers.
This is purely a data carrier consumed by plotPolygonOverlayOnTheMap. Plotting is additive (it does not recenter or zoom the camera). An overlay is uniquely identified by the tuple (propertyId, buildingId, floorId, polygonId) so it can be removed precisely via removePolygonOverlayFromTheMap.