feat(kernel): exact face and edge history model

Bodies can now carry the exact history of the operation that made them:
for each result face its origins among the operation's operands (kept,
modified, split, merged, or generated from a profile segment, cap, edge or
offset) and for each edge the faces it separates and the operand edge or
face pair it came from. History is recorded by the operation, never
sampled, and checked against the body when attached.

- history.rs: the vocabulary (moved from provenance.rs), History::check,
  identity, substitute (composes an operation with the one that made an
  operand, including bodies made from a sketch) and face-source propagation.
- One edge order for a body (body::edge_order), shared by tessellation and
  history, so history edge indices are the mesh's edge indices.
- Transforms report an identity history; placed_topology documents the
  face/edge order guarantee it relies on.
- provenance.rs keeps the geometric trace for operations that do not yet
  report history.

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

crates/kernel/src/splitface.rs

@@ -887,6 +887,7 @@ pub(crate) fn split_any(body: &Body, faces: &[usize], tool: &SplitTool) -> Resul
                 splits: body.splits.clone(),
                 face_sources: None,
                 regularization_protected: true,
+                history: None,
             },
             imp,
         ))