feat(kernel): modifiers report exact face and edge history

Fillets (local, loop, rolling ball, corner, variable, chord), chamfers
(cutters, local corners, loops, two sides), shell, draft, offset faces,
split face/body, delete face, patch/copy/stitch/trim/extend and
transforms record their history over [body] while they build: faces
rebuilt from the body's, blends in place of edges (corner patches in
place of the edges at the corner), shell walls as offsets, edges as
pieces of the body's or where two faces meet. Multi-step operations
compose each step. The push-face offset fallback now has history, and
the bore union composes its narrowed tool.

A reflection reorders a body's edges, so transforms now match edges by
identity (mirrored copies reported the wrong edges).

Refs #136

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01J53sR6gEaVt56soFDpTck8

crates/kernel/src/blend_variable.rs

@@ -229,6 +229,9 @@ pub fn fillet_variable_points(body: &Body, edge_at: Vec3, start: Vec3, points: &
                 subst.insert(e.id(), ne);
             }
         }
+        // The side edges at the ends are pieces of themselves; the contacts and end arcs are new.
+        let mut rec = crate::record::Rebuild::default();
+        rec.pieces(&subst);
         let mut new_faces: Vec<mt::Face> = Vec::with_capacity(faces.len() + 1);
         for (i, f) in faces.iter().enumerate() {
             let nf = if i == fr.i1 {
@@ -246,6 +249,7 @@ pub fn fillet_variable_points(body: &Body, edge_at: Vec3, start: Vec3, points: &
             } else {
                 (*f).clone()
             };
+            rec.face(&nf, f);
             new_faces.push(nf);
         }
         // The blend surface: rational quadratic arcs (tangent points and the edge point, middle
@@ -279,12 +283,14 @@ pub fn fillet_variable_points(body: &Body, edge_at: Vec3, start: Vec3, points: &
             vec![la.clone(), c1.clone(), lb.inverse(), c0.inverse()].into()
         };
         let blend = mt::Face::try_new(vec![wire], surf).map_err(|e| KernelError::Failed(format!("fillet face: {e}")))?;
+        rec.blend(&blend, [edge.id()]);
         new_faces.push(blend);
         let mut shells = solid.boundaries().clone();
         if let Some(sh) = shells.get_mut(si) {
             *sh = new_faces.into();
         }
-        Body::new(Solid::try_new(shells).map_err(|e| KernelError::Failed(format!("variable fillet produced an invalid solid: {e}")))?)
+        let out = Solid::try_new(shells).map_err(|e| KernelError::Failed(format!("variable fillet produced an invalid solid: {e}")))?;
+        crate::record::rebuilt(out, &[solid], &rec)
     })
 }
 
@@ -312,9 +318,11 @@ pub fn fillet_chord(body: &Body, edges: &[Vec3], chord: f64) -> Result<Body> {
             None => groups.push((r, vec![*p])),
         }
     }
-    let mut cur = body.clone();
+    // Each step's result carries its history over `[body]`.
+    let counts = crate::record::counts(&[body]);
+    let mut cur = crate::boolean_record::operand(body, 0, &counts);
     for (r, pts) in groups {
-        cur = crate::fillet(&cur, &pts, r)?;
+        cur = crate::record::after(crate::fillet(&cur, &pts, r)?, &cur, &counts);
     }
     Ok(cur)
 }