Nest drawings can require no parts, but the CAD Converter's quantity
spinner had a minimum of 1, so Edit Drawings in Converter threw
ArgumentOutOfRangeException as soon as such a drawing was selected.
Lowering the minimum to 0 lets the converter load it and hand the
drawing back with its quantity still 0.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>