Mascot-stage LoRA for the Mongle image character pipeline.

This LoRA is used by total.image_pipeline2.mascot_stage before the final pixel character text-to-image stage. It is different from Hadimeeee/mongle-character-lora.

Set this on the image character worker:

The existing code falls back to the local models/mascot_lora directory when MASCOT_LORA_SOURCE is not set.