Resolve HF Spaces gradio version conflict

Fix HF Spaces launch: pin gradio==4.31.5 and bind 0.0.0.0

Shorten HF Spaces short_description to <=60 chars

Merge HF Space starter (keep our README, pick up .gitattributes)

initial commit

Add HF Spaces YAML frontmatter and ANTHROPIC_API_KEY instructions

Initial commit: PID2Graph × Claude VLM evaluation + Gradio demo