CACAO v2/v3 confusion and varsig - are v3/varsig stale?

[bumblefudge]

Hey @ukstv @aarongoldman @oed --

Got a question from an implementer about the difference between CACAO v2 signature.t (eip191) and the varsig format that CACAO v3 uses to prefix the raw signature instead (which also doesn't correspond to the v2 signature types that are namespaces to L1s, i.e. caip122-eip191 instead of eip191, which is what threw off the implementer). Even more confusing, that spec's own example uses the v2 style type discriminant, not the varsig one. I couldn't remember where we landed on this, apologies if i promised a patch PR on a call and never delivered, which may well have been the case.

I was under the impression that this was kind of a Ceramic internal implementation thing for now, did other people build against this? If so, we should spin up calls again to finish the varsig specification and link to it from CAIP-191 (which is still in Draft). If not, maybe we mark both Stale for now and switch it back to Draft if a 2nd interoperable implementation is announced anywhere?

[oed]

@bumblefudge We are not actively pursuing CACAOv3 anymore since UCAN will no longer be compatible. Maybe we should just archive the v3 CAIP for now?