- update to Blender 4.2 LTS
- fix issue that can not find specular property in priniciple BSDF when applying virtools material.
- update blender manifest toml to let plugin works.
- there are various mesh works need to be fixed in later commits. this commit can not works normally on blender 4.2
- finish uv section of doc.
- fix issue about the wrong calc of coordinate system axis vector in flatten uv (change it from left hand to right hand).
- fix rail uv display text.
