Banner: lead with the instant 45s demo video, GPU run secondary

Add live-GPU banner + point CPU note to the GPU Space

Submission tags: + sponsor:modal (trained on Modal); note Modal in README

Update README.md

Fill submission links: demo video, social post, writeup

Deploy PixelLock GPU Space (llama.cpp + GGUF + GBNF + custom UI)

Deploy PixelLock GPU Space (llama.cpp + GGUF + GBNF + custom UI)

initial commit