Add the demo video and link it from the README

Link the social post in the README

Use a writable runtime HF cache; drop preload_from_hub

Default reviewer becomes Nemotron 3 Nano 4B, startup-loaded

Bring Nemotron 3 Nano back as the default reviewer

Claim achievement:offbrand and preload reviewer weights

Default the reviewer to Mellum 2, drop Nemotron

Make the Space self-compliant as a hackathon entry

initial commit