corpus: the filleted bracket partitioned into 30 blocks, meshed all-hex

filleted-bracket-blocks splits the bracket with SolidCraft's Split Body
into three slabs across its width, the fillet corner halved along its
diagonal and a four-cell O-grid round each hole; the corpus runner meshes
partitioned parts as one conforming block mesh. A heavy test clamps the
upright, loads the foot and checks hex8 and hex20 converge (hex20 tip
deflection within 0.1 % of a fine tet10 solution). Roadmap M5:
conforming interfaces done.

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

tests/corpus/filleted-bracket-blocks/README.md

@@ -0,0 +1 @@
+The filleted bracket split into 30 cells with SolidCraft's Split Body (three slabs across its width, the corner halved along its diagonal, an O-grid of four cells round each hole) so that every cell is a mapped block: conforming multi-block hex meshing.