FLUX.2 support

[jcelerier]

It looks like there is a path towards real-time FLUX.2 klein:

https://huggingface.co/black-forest-labs/FLUX.2-klein-4B
https://huggingface.co/vistralis/FLUX.2-klein-4b-INT8-transformer
https://developer.nvidia.com/blog/scaling-nvfp4-inference-for-flux-2-on-nvidia-blackwell-data-center-gpus/