Structured hex: extrude, revolve, sweep and mapped all-hex meshing (M5) (#40)

* Structured hex meshing: multi-level extrude and revolve, one-to-one sweep, mapped blocks (M5)

modelcraft_mesh::hex::hex_mesh meshes a face-tagged boundary surface with
hexahedra by the first structured method that fits: a straight or
rotational multi-level sweep (imprinted cross-section arrangement, cuts at
reflex corners, mapped/annulus/free regions), a one-to-one sweep through
rings of linking faces (least-squares affine layers with residual
correction), or a mapped logical cube (trivariate transfinite
interpolation). Interval assignment couples shared curves; boundary quads
carry B-rep face tags; the certified validity gate, a tiling check and a
fidelity check guard the output; hex20 mid-edge nodes go onto the faces.
Shape::face_surfaces exposes the analytic face surfaces; the corpus runner
gets a structured hex column.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NmAttHhUZTokgPeEJia8sm

* mesh.hex.generate: structured hex meshing as a command

Meshes one body, every body of the open design or an imported surface,
replaces the mesh, tags element faces with the B-rep faces (so sets by
geometry resolve) and reports per body the method, counts and quality.
The quality pass certifies each element once and feeds the validity gate
(quality::validity_gate_checks). Shape::size gives the cached body size
for defaults instead of a full measure.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NmAttHhUZTokgPeEJia8sm

* Hex: disk O-grids, convex interval cost, early size guard, hex20 corpus column

Smooth single-loop sections (cylinders, tori, vases) get a butterfly O-grid
instead of the free mesher; interval assignment raises counts by the
squared relative error so equal sides share increments evenly; a mesh far
beyond the element limit is refused before any work and mapped limits are
no longer swallowed. The corpus reports hex8 and hex20 quality.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NmAttHhUZTokgPeEJia8sm

* Catalogue: structured hex commands ready (mesh.hex.sweep, mesh.hex.mapped, mesh.hex.generate)

mesh.hex.sweep and mesh.hex.mapped run mesh.hex.generate with the sweeping
methods or the mapped one; mesh.hex.generate is the sweep entry's related
command. The planned M6 octree entry moves to mesh.hex.octree (its icon
renamed with it). docs/features.md regenerated.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NmAttHhUZTokgPeEJia8sm

* Docs: structured hex literature (B8), architecture, roadmap, parity; corpus hex column

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NmAttHhUZTokgPeEJia8sm

* Hex: simplify review fixes

Prepare each sweep frame's cross-section once (arrangement, cuts, fill)
and reuse it across refinement retries; candidate frames come from one
setup pass. Edge triangles come from the feature edges, layer counts go
through size::edge_divisions, sweep residual weights are computed once
per node, flux shape functions live on the stack, and the arrangement's
exact side test and distances serve the region probe. The engine takes
the boundary options mesh.tet.generate takes and names unnamed faces by
index like it; the corpus hex20 run reuses the winning method; the
mapped entry lists mesh.hex.generate too; the octree icon is redrawn
under its new id.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NmAttHhUZTokgPeEJia8sm

* Regenerate docs/features.md and docs/meshing/corpus.md after rebasing

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NmAttHhUZTokgPeEJia8sm

* Regenerate docs/features.md and docs/meshing/corpus.md after rebasing onto main

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NmAttHhUZTokgPeEJia8sm

* Regenerate docs/features.md and docs/meshing/corpus.md after rebasing onto main

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NmAttHhUZTokgPeEJia8sm

* Regenerate docs/features.md and docs/meshing/corpus.md after rebasing onto main

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NmAttHhUZTokgPeEJia8sm

* Regenerate docs/features.md after rebasing onto main

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NmAttHhUZTokgPeEJia8sm

* Regenerate docs/features.md after rebasing onto main

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NmAttHhUZTokgPeEJia8sm

* Regenerate docs/features.md after rebasing onto main

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NmAttHhUZTokgPeEJia8sm

---------

Co-authored-by: jyviko <2501648+jyviko@users.noreply.github.com>
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

docs/architecture.md

@@ -79,7 +79,17 @@ Rules beyond the layer order:
    recombination (Lee and Lo 1994) and one uniform split that lands on the boundary nodes, then
    smoothing and untangling; every quad is checked with exact predicates. One `SizeField` trait
    (`modelcraft-mesh::size`) sets interior sizes and edge divisions, with even counts per loop.
-   Mapped and swept hex build on these face meshes. Without geometry, `mesh.block`
+   Mapped and swept hex build on these face meshes (`modelcraft-mesh::hex`, `mesh.hex.generate`):
+   the B-rep topology is recovered from the face-tagged surface; a body is extruded (straight
+   multi-level sweep: the levels' outlines imprinted into one cross-section, cut at reflex corners,
+   regions mapped, O-gridded or free-meshed, then stacked), revolved (the same in a rotating
+   frame), swept one-to-one through rings of linking faces (least-squares affine layers, Roca and
+   Sarrate 2010), or mapped as a logical cube (Gordon and Thiel 1982); interval assignment
+   couples the counts of shared curves. Nodes on analytic faces (`Shape::face_surfaces`) are
+   exact, hex20 mid-edge nodes go onto the faces, boundary quads carry B-rep face tags, and the
+   result passes the certified validity gate plus tiling and fidelity checks. A body no method
+   fits gets each method's reason.
+   Without geometry, `mesh.block`
    (`modelcraft-mesh::block`) meshes one six-sided block from its eight corners and optional
    circular or elliptical edges by the same edge-based transfinite interpolation, as hex8, hex20,
    tet4/tet10 (Kuhn's six tetrahedra per cell) or wedge6, with grading; blocks join where their