The nightly vLLM image puts ALL MHC code in layers/mhc.py (not kernels/mhc/).
It imports tilelang at top level and JIT-compiles kernels.
Replace the entire file with pure PyTorch implementations using
direct_register_custom_op for mhc_pre, mhc_post, mhc_fused_post_pre,
and hc_head_fused_kernel. No tilelang dependency at all.
Also removes the separate mhc_torch_ops.py and kernels/mhc/ patches
which don't apply to the nightly image layout.