core: Vertical Shafts on the shared Core cave planner (L139, v237; 15/16 seeds)

Shaft mode reuses PlanResolvedCavernNetworkV1 with a capped full-height cylinder primitive (shapeKind=1), ledges,
access bores and cross links; 11 VerticalShaftParams fields mapped. Basal law: arrival 2-3 to a walkable terminal
landing; drops/climbs stay reporting tiers. Seed 2 fails shell/seams at the 2-3 arrival mouth (3 variants tried,
stopped per AGENTS.md). Whole view faster than assembler/world in 8/8 cells; near-ready slower in 7/8.
Source/: VoxelForgeCoreAdapter.cpp.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016dhxM43dnWvUu2B5Ph1iG1

Source/VoxelForge/Private/VoxelForgeCoreAdapter.cpp

@@ -144,13 +144,15 @@ bool ConfigureCoreGeometryStratum(const FStrateSlot& Slot, ECaveGeneratorType Ge
         return true;
     case EVoxelForgeCoreGeneratorRecipe::NativeCaves:
         if (GeneratorType != ECaveGeneratorType::TunnelNetwork
-            && GeneratorType != ECaveGeneratorType::Underwater)
+            && GeneratorType != ECaveGeneratorType::Underwater
+            && GeneratorType != ECaveGeneratorType::VerticalShafts)
         {
-            OutError = FString::Printf(TEXT("Strate %d selects NativeCaves but its generator archetype is not TunnelNetwork/Underwater."),
+            OutError = FString::Printf(TEXT("Strate %d selects NativeCaves but its generator archetype is not TunnelNetwork/Underwater/VerticalShafts."),
                 Slot.StrateIndex);
             return false;
         }
-        Item.generatorKind = "Caves";
+        Item.generatorKind = GeneratorType == ECaveGeneratorType::VerticalShafts
+            ? "VerticalShafts" : "Caves";
         Item.recipeId = "Core.Caves.PrimitiveField";
         Item.recipeVersion = 1;
         Item.boundDispatchPath = "Core native cave graph uses resolved room and tunnel records";