DxfImporter now filters ETCH entities (like BEND) since etch marks are
generated from bends during export, not cut geometry. GeometryOptimizer
no longer merges lines/arcs across different layers and preserves layer
and color on merged entities. EntityView draws etch marks directly from
the Bends list so they remain visible without relying on imported ETCH
entities.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
BEND layer lines were being imported as cut geometry alongside the
separate Bend object detection, causing duplicate dark lines in nests.
Skip BEND layer entities in DxfImporter since bend detection reads
directly from the raw CadDocument.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Move DxfImporter, DxfExporter, NestReader, NestWriter, ProgramReader,
and Extensions into a new OpenNest.IO class library. The WinForms project
now references OpenNest.IO instead of ACadSharp directly.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
