feat: use pointer-aware author avatars

[QuickMythril]

Summary

• Resolve each visible feedback author name to its current owner address before fetching a pointer-aware account avatar.
• Retain initials in browser and unsupported-Home modes; validate Blob images and retry PENDING.
• Document the owner-address boundary in the in-app developer reference.

Validation

• npm test
• npm run build
• Browser fallback visual check

Follow-up

• Embedded Home acceptance with a real pointer avatar, including PENDING and legacy behavior.

Includes the existing canonical 0BSD license documentation commit.