Add vanilla ProteinMPNN weights

Revert Dockerfile — vanilla weights uploaded manually via HF web UI

Download vanilla ProteinMPNN weights at build time

Fix citation: Galindo and Maejima et al.

Correct Step 2 description; update README to match HF Space

Rename to Antibody to Intrabody Pipeline

Bold skip-step-1 note; separate citation lines

Clean history — remove LFS PNG commits