Farcaster

Another interesting Farcaster idea: move signers onto hubs

- Zero cost to add a new app
- Zero friction to add a new app 

Not feasible with CRDTs could accidentally cause a new signer to kick out your first one which would be really bad. 

But with snapchain this is doable. h.t to @stephancill for the idea.

This would be a great reversion

Right now, deciding to be a client (ie. an app that can write to hubs) requires not only betting on FC, but making users pay before they can use your app

By getting rid of the latter, it reduces risk to just platform risk and likely will enable FC read-only apps to become clients more easily