Root cause of 25ms (vs expected 2.5ms):
1. ElementAccumulator was half_t → now float (FP32 accumulation)
2. Missing OpClassTensorOp → was defaulting to OpClassSimt (CUDA cores only)
3. Missing arch::Cu10 → was defaulting to arch::Sm61
With these fixes it should use __ivcorex_matrix_mad_f32x4_f16x4 (TCU)
same as moe_cutlass_batched.cu which benchmarked at 2.462ms.