feat: free-form cut-outs stay exact in sheet-metal flat patterns (#692)

Sheet-metal cut-outs and base flange outlines drawn with ellipses, splines or text stay exact curves in the flat pattern and the unfolded body; the folded body follows them with tangent arcs within 0.001 mm (#659).

crates/geom/src/lib.rs

@@ -8,6 +8,7 @@
 #![deny(clippy::unwrap_used, clippy::expect_used, clippy::panic, clippy::unimplemented, clippy::todo, clippy::unreachable)]
 #![forbid(unsafe_code)]
 
+mod arcfit;
 pub mod brep;
 pub mod bspline;
 pub mod env;
@@ -18,6 +19,7 @@ mod profile;
 pub mod tspline;
 mod vec;
 
+pub use arcfit::MAX_FIT_PIECES;
 pub use mesh::{Aabb3, InsideIndex, Mesh, MeshMeasure};
 pub use plane::Plane;
 pub use profile::{Loop2, MAX_BEZIER_DEGREE, Region2, Seg2, bezier};