mesh.cells: tet cells meet hex cells through pyramids

With "transition": "pyramid" (the default; "tie" keeps the old join) a tet
cell is meshed after the hex cells, with a pyramid on every hex face of its
cuts and its tetrahedra on the pyramids' sides: one conforming mesh, no tie.
Where it cannot be built the cell says why (no_pyramids) and is tied. The
apex height is 0.4 of the quad's edge, so pyramids on faces meeting at a
right angle do not cross.

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

crates/engine/src/catalogue.rs

@@ -359,7 +359,7 @@ pub static CATALOGUE: &[Capability] = &[
         "Partitioned Mesh",
         Mesh,
         "Structured Hex",
-        "One mesh of a partitioned part, a method per cell (hex, tet, or all hex as conforming blocks); cells joined across partitions",
+        "One mesh of a partitioned part, a method per cell (hex, tet, or all hex as conforming blocks); cells joined across partitions, tet cells to hex cells through conforming pyramids",
         &["mesh.hex.blocks"],
     ),
     ready(
@@ -393,7 +393,6 @@ pub static CATALOGUE: &[Capability] = &[
         "M5",
         "Find sweepable and mappable regions of 3D parts (extruded cross-sections are already cut into blocks by Hex Mesh)",
     ),
-    soon("mesh.transition", "Transition", Mesh, "Structured Hex", "M5", "Conforming tet–hex interfaces with pyramids"),
     ready(
         "mesh.hex.octree",
         "Octree Hex",