plotPolygonOverlayOnTheMap

Plot a free-form polygon overlay (restricted "do-not-enter" area) on the property plotting layer. Purely additive — it does not recenter or zoom the camera. The overlay is keyed by its (propertyId, buildingId, floorId, polygonId) tuple for precise removal. Fail-closed/quiet: malformed geometry is logged and skipped, it never throws into the caller.