Add zero-copy procedural BLAS overloads that take the AABB build input
straight from an existing device buffer instead of memcpy-ing a host span
through Mesh::aabbBuffer — the input-source companion to #36's refit work.
A GPU compute producer (e.g. a GPU-resident particle system) can now feed a
moving procedural BLAS that builds/refits each frame with no host round-trip.
Vulkan: new BuildProcedural(VkDeviceAddress, count, ...) and
RefitProcedural(VkDeviceAddress, count, ...) feed the device address directly
into VkAccelerationStructureGeometryAabbsDataKHR; the host-span path is
refactored to share RecordProceduralBuildFromAddress and is otherwise
unchanged.
WebGPU: device-buffer BuildProcedural/RefitProcedural copy the boxes GPU->GPU
into the mesh heap (new wgpuRegisterMeshBLASDeviceAabbs / wgpuRefitMeshBLAS-
DeviceAabbs bridge fns) and wrap them in a single root leaf bounded by a
caller-supplied worldBounds — no wasm round-trip, blasAddr stable across refit.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>