SD3.5 MLX runtime source derived from DiffusionKit at commit
498e5dba5fb48b0f01cb6b5c2292a6dbea67a317:
https://github.com/argmaxinc/DiffusionKit

Original work by Argmax, Inc. and contributors, released under the MIT License.
Rapid-MLX modifications remove Torch/CoreML-only dependencies, require reviewed
local asset roots, update the MLX attention API, expose progress/cancellation,
and narrow the adapter to SD3.5 Large text-to-image generation.
