Support for Qwen-Image Eligen Lora like Diffsynth Studio.

**Is your feature request related to a problem? Please describe.**
This Feature will really help to make workflows without using Diffsynth.

**Describe the solution you'd like.**
same implementation but natively in Diffusers.

**Describe alternatives you've considered.**
Diffsynth Studio is the only alternative.

**Additional context.**
Best Regional Prompting for Qwen and Flux (DIT models only), entity-based. mask overlapping is not an issue.

No file, test, or entry point is named. First clarify the desired Qwen-Image Eligen LoRA behavior and compare it with Diffsynth Studio; done should mean native Diffusers support for regional, entity-based prompting, including the stated overlapping-mask behavior.

Rédigé par le modèle d'indexation à partir du texte de l'issue.