Add argument validation to EllipseConverter.Convert for tolerance and
semi-axis parameters. Narrow bare catch in Extensions.cs spline method
to log via Debug.WriteLine. Remove unused lineCount variable from
SolidWorksBendDetectorTests.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Add EllipseConverter static class with foundational methods for converting
ellipse parameters to circular arcs: EvaluatePoint, EvaluateTangent,
EvaluateNormal, and IntersectNormals. All 8 unit tests pass.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>