Where a project length-unit scale came from (#7395), shared by the unit
walk in unit-extractor.ts and the parse in columnar-parser.ts.
declared when the project's IFCUNITASSIGNMENT declares a LENGTHUNIT
that resolves; default when the scale is the unconfirmed 1.0 (metres)
every other path falls back to (#2104).
Where a project length-unit scale came from (#7395), shared by the unit walk in
unit-extractor.tsand the parse incolumnar-parser.ts.declaredwhen the project's IFCUNITASSIGNMENT declares a LENGTHUNIT that resolves;defaultwhen the scale is the unconfirmed 1.0 (metres) every other path falls back to (#2104).