convrot for int8 and fp4

**Is your feature request related to a problem? Please describe.**

to use https://huggingface.co/Comfy-Org/MiniMax-H3/blob/main/diffusion_models/minimax_h3_fl2va_pruned_int8_convrot.safetensors

**Describe the solution you'd like.**

https://arxiv.org/pdf/2512.03673

**Describe alternatives you've considered.**
A clear and concise description of any alternative solutions or features you've considered.

**Additional context.**
https://github.com/feice-huang/ConvRot
https://github.com/BobJohnson24/ComfyUI-INT8-Fast

Start by reading the linked ConvRot repository and the arXiv paper, then inspect how diffusers currently handles the referenced minimax_h3_fl2va_pruned_int8_convrot.safetensors model. The issue does not name files, tests, or an entry point, so first establish the intended int8 and fp4 scope and how completion will be validated.

Written by the indexing model from the issue text.