FEP-8b32: Object Integrity Proofs

https://codeberg.org/fediverse/fep/src/branch/main/fep/8b32/fep-8b32.md

Object proofs are great, but I'm not sure if they're super necessary. Their main benefit over HTTP signatures seems to be that you can forward them to other servers without modifying the object and thus the 2nd degree remotes have an easier time verifying the objects. However Shoot doesn't forward activities like this, everything passes through the channel actor for moderation purposes...

Shoot *could* preempt forwarding to other channel members and save the group some time, but then for rejections we need also need to send all members the reject, not just the sender. This could be an abuse vector...?

Read fep/8b32/fep-8b32.md first, then compare its forwarding and verification implications with Shoot's channel-actor moderation flow. A useful outcome is a clear decision on whether Shoot should implement Object Integrity Proofs, including how rejection delivery and the identified abuse concern should be handled.

Written by the indexing model from the issue text.