Native-Go authority for the Lux VM state roots — the byte-for-byte
reference the GPU accelerators (CUDA/HIP/Metal/Vulkan/WGSL) match.
- crypto/hash/keccak.go: ComputeKeccak256{,Array} via
sha3.NewLegacyKeccak256 (Ethereum Keccak-256, 0x01 pad) — NOT
sha3.Sum256 (FIPS-202 SHA3, 0x06 pad), which would diverge from the
GPU kernels and split consensus.
- crypto/merkle: Root/LeafHash/NodeHash/EmptyRoot. leaf=keccak(0x00|d),
node=keccak(0x01|L|R), RFC-6962 lone-right promotion, keccak256("")
empty root. Shape depends only on leaf count -> bit-identical to the
gpu-kernels lux::merkle::merkle_root spec across all backends.
Reproduces the spec's 7 canonical KAT vectors byte-for-byte
(n=0,1,2,3,4,5,8). CGO_ENABLED=0 clean, pure-Go, luxfi deps only.
Computation + tests ONLY — consensus wiring (fill xvm StandardBlock.Root
+ executor activation gate) is the separate next phase.
