Feature - Generate and share QR code from signature

Just an idea - would it be pretty cool if I could sign a message and get a QR code picture containing signed information which can be shared to social media and later verified directly by upload the pic?

The issue names no files, tests, or entry points. Begin by mapping the existing message-signing and verification flows, then define how QR encoding, sharing, image upload, and verification should work before implementation; done requires a clear end-to-end design and acceptance criteria.

Written by the indexing model from the issue text.