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 <[email protected]>
Claude-Session: https://claude.ai/code/session_01J53sR6gEaVt56soFDpTck8

ROADMAP.md

@@ -48,7 +48,7 @@ PCB / Package, Render, Animation, Simulation, Manufacture/CAM, Drawings.
 | M2 | Robust modelling: coplanar booleans in the kernel, holes (placed on faces and on sketch points), threads (cosmetic, then modelled), patterns, mirror, shell, draft, split, construction geometry | in progress | 16 |
 | M3 | General fillets and chamfers (curved edges, chains, vertex blends); saddle rolling-ball surfaces now use continuous seam sections and arc-length fitting with shared contact boundaries and bounded accuracy checks | in progress | 30 |
 | M4 | Files: STEP import (done — [docs/step-import.md](docs/step-import.md)), 3MF export and 3MF/STL import as mesh bodies (done), constant-section parametric mesh reconstruction, DXF sketches, OBJ import | in progress | 6 |
-| M5 | Persistent naming of faces and edges (plan/adr/0002): faces named from their history (sketch curve sides, caps, revolve sections, primitive sides, blends, pattern/mirror copies; split pieces numbered), edges by their faces; fillets/chamfers, sketches on faces, shell/draft/offset/replace faces, hole placements, joint origins and face appearances resolve by name first and warn when the entity split or vanished: done. sheet metal edges by base sketch line and flange side, shell inner faces, sweep and loft roles: done. Left: kernel-reported face history (exact through coincident surfaces) | in progress | 20 |
+| M5 | Persistent naming of faces and edges (docs/book/src/dev/naming.md): faces named from their exact kernel-reported history (sketch curve sides, caps, revolve sections, primitive sides, blends, shell inner walls, pattern/mirror copies; split pieces told apart by the faces around them, lumps of a cut body named after their faces), edges by their faces; fillets/chamfers, sketches on faces, shell/draft/offset/replace faces, hole placements, joint origins and face appearances resolve by name first and warn when the entity split or vanished: done. sheet metal edges by base sketch line and flange side, shell inner faces, sweep and loft roles: done. kernel-reported face history: done (merged faces answer to every name; operations without history yet fall back to geometric names, flagged unverified; format 14 keeps older designs' geometric names). Left: history through sheet metal, plastic, surface and emboss features; FaceSource certificates through history | in progress | 20 |
 | M6 | UI depth: selection feedback and origin (done), timeline editing (done: hover and selection highlight modifier faces, including fillets and chamfers; edit feature, history marker drag, reorder with dependency checks, suppress, rename, delete with dependents, re-resolved references; redefining selections refreshes persistent edge/face references while retaining feature identity and dimension names), right-docked dialogs (done), live previews for every feature dialog (done), keyboard-first commands with on-canvas value boxes and sketch inline dimensions (done), drag manipulators with automatic join/cut (done: extrude incl. two sides, fillet, shell, hole depth, move, pattern spacing, revolve rotator; taper handle open), dark theme (done), right-click menu with Repeat (done), measure tool (done), section analysis (done), selection filter (done), drag-solve of sketch points (done); appearance controls now preserve body/face/component targeting, named transparent looks, reuse/search and override removal; preferences | in progress | 6 |
 | M7 | Sweep, loft (incl. to a point), rib and web (to next / depth), emboss (planar faces and exact radial emboss/deboss of bounded orthogonal profiles on complete exterior cylinders/sleeves), thread (cosmetic, and modelled M3–M20 outside and inside: the ISO profile screwed in as a faceted cut), coil (smooth B-spline helical walls), pipe, pattern on path, patterns of bodies and components, replace face (parallel), align, remove, feature copy/paste: done. Unique eligible cylindrical targets are inferred for new Emboss features. Left: general curved-face emboss and exact (unfaceted) modelled threads | in progress | 12 |
 | M8 | Surface workspace | deferred | — |
@@ -183,9 +183,9 @@ PCB / Package, Render, Animation, Simulation, Manufacture/CAM, Drawings.
   offset surfaces and pcurve-only edges are not read yet,
   and assembly components are flattened into bodies. Closed periodic faces (torus, B-spline
   bands) are split in two for meshing; measure() uses a finer tolerance for small radii.
-- Persistent naming (plan/adr/0002) names faces from their history and edges by their faces;
-  references resolve by name first and warn when the entity split or vanished. Kernel-reported
-  face history (exact through coincident surfaces) is not wired in yet.
+- Persistent naming follows the kernel's exact face history (docs/book/src/dev/naming.md):
+  references resolve by name first, follow splits and merges, and warn when the entity split,
+  merged or vanished, or was found by geometry only (operations that report no history yet).
   New planar sketch attachments use exact box, extrusion cap/side and immutable imported-face
   source certificates with checked target and author occurrence paths. A missing or changed
   source fails explicitly; Redefine Sketch Plane previews reattachment or a fixed plane while