Variable ifcElementContainmentConst

ifcElementContainment: inspect.dataModel.Inspection = ...

Opt-in via InspectDataModelParams.checkIfcElementContainment.

Flags IFC building / furnishing elements that appear as the child side of an aggregation relationship under a spatial structure (IfcSite / IfcBuilding / IfcBuildingStorey / IfcSpace). IFC4 convention is to attach elements to their spatial container via IfcRelContainedInSpatialStructure, not IfcRelAggregates — flattened exports often collapse both into IfcRelAggregates, which slips past structural checks.

Needs params.schema (uses typeMatchesOrInherits to walk super-type chains for the "is this an IfcElement?" / "is this a spatial structure?" decisions).