FLUX.2-klein needs diffusers from git (Flux2KleinPipeline) + Qwen3 text encoder deps

Upgrade to FLUX.2-klein-4B (Apache, 4B, sub-second) via Flux2KleinPipeline

Fix ZeroGPU crash: import spaces first, real @spaces.GPU, FLUX.1-schnell (#1)

initial commit

Duplicate from gradio-templates/text-to-image-gradio-template