ACadSharp Arc.StartAngle/EndAngle store values in degrees (DXF spec groups
50/51). The previous code passed Math.Atan2 results (radians) directly,
causing silent geometry corruption. Also hardened the arc export test to
assert angles are in degree range (0..360).
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Remove unnecessary System, System.Collections.Generic, System.IO, and
System.Linq using directives that were flagged by IDE analyzers. Also
includes minor whitespace and code style normalization.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
- Remove DotNetZip package from PepLib.Core.csproj
- Update DrawingReader, NestReader, and ZipHelper to use System.IO.Compression.ZipArchive
- Simplify stream handling and improve resource disposal
- Keep behavior consistent for loop/plate detection and extraction