Explore silent payments UX

[GBKS]

We had a great learning call today about silent payments. The protocol is in a refined stage and there's work going into an initial implementation. This is a great time for designers to join and explore how this technology might surface for users, the use cases it enables, benefits and drawbacks.

This initiative is in the same vein as #607 around covenants. We could also create a design challenge for silent payments.

During this call, as well as the covenants and FROST calls, I realized that we have a lot of foundational work that we can build on in our existing reference designs in the guide. For example, we can use the mock-ups for the daily spending wallet send flow and Payjoin case study to come up with a a silent payments send flow. With silent payments having a similar goal to BOLT12 in lightning (in therms of having a static payment code), there might be overlap there as well.

I think good first step would be to create a collaborative doc to outline what areas of the user experience would be good to explore, then piece in existing work we have and start tweaking it.

If someone wants to just go ahead and do this exploration, go for it. If there's interest in a group effort in the community, we can set that up as well. Either way, leave a comment to share your thoughts on this initiative.

[mouxdesign]

Adding in link to https://github.com/BitcoinDesign/Guide/issues/1066 created for Silent Payments as well.

[yashrajd]

We've been tracking progress of this in the silent payments PR. We can close this issue once this PR is merged in.