feat(doc): persistent names follow the kernel's exact face history (#136)

Why: every reference a user makes to a face or edge (fillet and chamfer
edges, sketches on faces, shell/draft/offset faces, joints, appearances)
is stored as a name and found again after any upstream edit. Those names
were re-derived by sampling points of each face and voting, and pieces
of a split face were numbered by where their centres lay. After an
upstream edit that splits, merges, mirrors or shrinks a face, a fillet
or sketch could silently re-attach to the wrong face, and nothing told
the user. The kernel now reports exact history for its operations, so
names follow it and fail loudly instead of guessing.

- crates/doc/src/lineage.rs: a feature's kernel histories composed into
  one lineage over nameable operands (bodies before the feature, moved
  copies, shell cavities, tools named by role: sketch curve, cap, box
  side, imported face). Instrumented: extrude/revolve/sweep/loft tools,
  join/cut/intersect, lumps after a cut, fillet/chamfer, shell, draft,
  split face/body, pattern/mirror (bodies and features), combine,
  boundary fill, move/scale, offset/delete face, thread, import.
- crates/doc/src/history_names.rs: names from lineage; split pieces told
  apart by the faces only they touch (F2:top#[F2:side:l4,F4:side:l4]),
  merged faces answer to every name (aliases), lump bodies ordered by
  their faces' names instead of shell order.
- crates/doc/src/name_lookup.rs, piece_names.rs: references resolve by
  exact name, alias or bounding faces, else nearest piece with a
  warning; names worked out from geometry (operations without history)
  are reported when only geometry decided.
- Format 14: names stored by older formats get a legacy mark and are
  found as the build that saved them found them (some geometric names
  name a face history names differently: a tube's outer wall was named
  after its inner circle). New corpus file saved by 9a979cf.
- kernel: Body::lumps carries each piece's history over the whole.
- Adversarial tests: split, merge, mirrored twins, shrink to a sliver,
  moving cut with body pieces, history-less bodies, certified sketch.
- docs/book/src/dev/naming.md describes the real mechanism and why.

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

crates/doc/src/clipboard.rs

@@ -80,6 +80,10 @@ impl FeatureKind {
 
 /// Remap persistent topology tokens without rewriting arbitrary user expressions or labels.
 pub fn remap_topology(name: &str, ids: &BTreeMap<u64, u64>, bodies: &BTreeMap<String, String>) -> String {
+    // An older design's name keeps its mark; what follows it is remapped as any name.
+    if let Some(old) = crate::naming::legacy_name(name) {
+        return format!("{}{}", crate::naming::LEGACY_MARK, remap_topology(old, ids, bodies));
+    }
     // Imported names belong to the complete canonical body prefix, even when that prefix
     // happens to contain text resembling a feature token.
     if let Some((body, suffix)) = name.rsplit_once(":face:")
@@ -91,7 +95,9 @@ pub fn remap_topology(name: &str, ids: &BTreeMap<u64, u64>, bodies: &BTreeMap<St
     let mut at = 0;
     while at < name.len() {
         let rest = &name[at..];
-        if rest.starts_with('F') && (at == 0 || matches!(name.as_bytes().get(at - 1), Some(b'@') | Some(b':') | Some(b'|'))) {
+        // A feature token starts a name, or one inside it: after `@`, `:` or `|`, or in a
+        // piece's list of the faces around it (`[`, `,`).
+        if rest.starts_with('F') && (at == 0 || matches!(name.as_bytes().get(at - 1), Some(b'@' | b':' | b'|' | b'[' | b','))) {
             let end = rest.as_bytes().iter().skip(1).take_while(|b| b.is_ascii_digit()).count() + 1;
             if end > 1
                 && matches!(rest.as_bytes().get(end), Some(b':') | Some(b'.'))