fem: pyramid5 element (solver, quality, decks, VTK)

A five-node pyramid, the conforming transition between a hexahedron's face
and tetrahedra: Bedrosian's rational shape functions with a collapsed (Duffy)
Gauss rule, a certified Jacobian on the base square with exact volume, a
scaled Jacobian, C3D5 / CPYRAM / LS-DYNA degenerate solid, VTK_PYRAMID and
the binary mesh code 13. A distorted hex8-pyramid5-tet4 transition mesh
passes the patch test and uniaxial tension exactly.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo

crates/fem/src/basis.rs

@@ -207,6 +207,7 @@ impl Basis {
             ElementKind::Tet4 => Basis::Tet4,
             ElementKind::Tet10 => Basis::Tet10,
             ElementKind::Wedge6 => Basis::Wedge6,
+            ElementKind::Pyramid5 => Basis::Pyramid5,
             ElementKind::Hex8 => Basis::Hex8,
             ElementKind::Hex20 => Basis::Hex20,
         }