Adds Dictionary<string,string> VariableRefs to Motion (cleared on Rotate/Offset) and string VariableRef to Feedrate, with deep-copy Clone() support, so post processors can emit variable references instead of literal coordinate values.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Adds immutable VariableDefinition record to OpenNest.CNC with name,
expression, resolved value, inline, and global flags. Fixes namespace
collision in PatternTilerTests and PolygonHelperTests caused by the new
OpenNest.Tests.CNC namespace.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
