Based on УКД (universal correction document) template analysis.
Multiple <columns> with UUID allow rows to use independent
column grids. Merges and named areas also reference column sets.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Based on real templates from 1C:Accounting — invoice (horizontal
areas, 33 columns) and label (vertical area, drawing, barcode).
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>