Function emit_cutlass_nvfp4_group_gemm 

pub fn emit_cutlass_nvfp4_group_gemm(cfg: &CutlassNvfp4Gemm) -> String

Emit our compiler’s CUTLASS Blackwell NVFP4 grouped GEMM (MoE) — all G experts in ONE kernel launch via CUTLASS GroupProblemShape + per-group pointer arrays. This is the fusion edge on the GPU MODE nvfp4_group_gemm leaderboard: the reference launches G separate GEMMs; we launch one grouped kernel over all experts (no per-expert launch overhead, one wave of tensor-core work). Validate on the B200 runner.