Add joint task-force group-shot image (assets/group_shot_v1.png)

Org card fix + hero art: superhero avatars, team banner, markdown card (drop app_file so card renders README.md)

Character showcase org card: 3-tier (5 organs + 10 sub-organs + 8 PhD council), HF-mascot avatars, deep-purple/gold. Doctrine v7, zero marketing, zero Putnam.

org-card: replace animated SVG with PNG hero (HF strips SMIL in org-card renderer)

initial commit