Add a top-level MegaMoE helper that handles source/runtime FP4 weight granularity before applying the existing MegaMoE weight layout transform.
Use the helper from the synthetic MegaMoE benchmark so SGLang can later follow the same contract for GLM-5.2 NVFP4 group16 checkpoints.
Tested: PYTHONPYCACHEPREFIX=/private/tmp/deepgemm_pycache python3 -m py_compile deep_gemm/__init__.py deep_gemm/mega/__init__.py tests/test_mega_moe.py
Tested: git diff --check
Not-tested: CUDA build, SM100/B300 runtime, and GLM-5.2 accuracy validation are not available locally.
2c7543130b
