Function classify_type_name 

pub fn classify_type_name(type_name: &str) -> u8

Classify a scanned STEP keyword into the prepass class byte: a named-arm code for the exact keywords the serial pre-pass matches, plus the geometry-job / type-candidate FLAG bits from the same helpers it calls (has_geometry_by_name, IfcType::is_subtype_of). Byte-identical span collection and job discovery follow from using the identical predicates at scan time.