kernel: exact projection, section and iso curves exported; SMLib at the fork's integration head

(not built: base in progress)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017itGh5fpMEousnZ91cYcVt

crates/kernel/src/lib.rs

@@ -188,7 +188,9 @@ pub use native::{body_from_smlib, smlib_body};
 pub use native::{brep_record, decode_native_body, encode_native_body, native_preview_mesh};
 pub use offset::with_same_surface;
 pub use ops::{BoolOp, boolean, half_space, join_apart, place_matrix, split_by_plane, transform, transform_matrix, union_apart};
-pub use point_path::{PathPiece, PointPath, SpaceBezier, curve_path, edge_path, sketch_record_curve, sweep_point_path_with};
+pub use point_path::{
+    PathPiece, PointPath, SpaceBezier, curve_path, edge_path, face_section_along, iso_curves, project_onto_face, sketch_record_curve, sweep_point_path_with,
+};
 pub use polybool::faceted_boolean;
 pub use polyhedron::{HalfSpace, convex_polyhedron, draft, offset_faces, shell};
 pub use prism::{PLANAR_FIT_TOL, extrude_planar_regions, planar_regions_boolean};

crates/smlib/SMLIB_REV

@@ -1 +1 @@
-eedfa514371f80697c66472b40bda7d0e30146f5
+964474aef3baeaca3a1291182eb912297265b3e9