ocs_doc_api: outstanding methods — loft + bulge-arc polyline profiles

- Loft{profiles} op (append-only); executor resolves each profile to curve sets
  all-or-nothing; backend loft() -> brep::loft on XY plane; facade solids().loft.
- entity_to_profile_curves: convert LwVertex.bulge to geom2d::Curve::Arc via
  bulge_arc_segment (theta = 4*atan(bulge)), so bulged polyline profiles sweep
  correctly instead of erroring Unsupported.
- spec loft; api_reference + binding_schema regenerated; mocks + baseline.
- Tests: loft_two_profiles_produces_solid, bulge_arc_polyline_profile_converts_to_arc
  (semicircle radius=5 for bulge=1) -> 612 host lib + 3 consistency green.

crates/ocs_doc_api/tests/spec_wire_consistency.rs

@@ -63,6 +63,7 @@ fn operation_variants() -> Vec<String> {
         Operation::CreateRasterImage(ocs_doc_api::ops::RasterImageSpec {
             file_path: String::new(), insertion_point: [0.0; 3], u_vector: [0.0; 3], v_vector: [0.0; 3], size: [0.0; 2],
         }),
+        Operation::Loft { profiles: vec![] },
     ];
     // Derive the variant names by serializing a probe of each and reading the
     // bincode variant index -> name map is not available; instead match by
@@ -151,6 +152,7 @@ const OPERATION_BASELINE: &[&str] = &[
     "SetAttribute",
     "SetViewportView",
     "CreateRasterImage",
+    "Loft",
 ];
 
 /// Recorded baseline of the `Query` variant order.