6.2

Another big update, bringing a change to the contouring engine that greatly improves how keyholed geometry is processed. Additionally, 15-20% performance has been gained and a bunch of bugs were fixed across multiple areas. The viewport was also moved to an actively maintained variant of Veldrid.

- Using NET 9.0 now.
- Experimental adoption of ppy.Veldrid packages, as a maintained Veldrid project.
- Fixed regression in PA search feature.
- Fixed multiple issues in reference layer handling.
- Fixed regression in multi-polygon flip scenarios.
- Fixed regression in side rays for proximity biasing.
- Fixed regressions in lens distortion code.
- Applied some fixes to avoid artifacts in keyhole handling for sequential geometry operations.
- Big change to the shape engine sequence.
 - Historically, we applied contouring on top of the keyholed structure, which caused rounding in the keyhole region.
 - Now, if appropriate, we collapse keyholes to get the outers and inners.
  - Outers are rounded as normal. Inners see rounding with inverted assignment.
  - Outers and inners are then passed to the keyholer for combination.
  - Benefit is that the keyholed region is not rounded at all now, avoiding undue influence on the shape.
  - This will change existing results for these scenarios (unless the legacy mode is enabled), but the results will be correct now.
- Extensive code refactoring.
- 15-20% performance increase.
 - Adjusted how the result package works, avoiding potential contention.
 - Also more multithreading usage across various libraries in DesignLibs.
- Layout file improvements in GeoCore.