UI: GritAI engineered/industrial design system (dark, grit-orange, Archivo+IBM Plex)

add demo.png (2x2 sample grid)

fix: gradio 5.38.2 (4.44 broke on new huggingface_hub HfFolder); ZeroGPU startup preload

add api_name=generate for programmatic validation

#6 AI Image Generator — FLUX.1-schnell on ZeroGPU (private review build)

initial commit