"thread" visibility

a default visibility for threads/replies, unlike any other.

it shows to those who can see the thread.

requirements

posts need to inherit visibility from somewhere. another post, more specifically, for compatibility with groups later on.

this should be the OP's post.

for federation with instances that don't support it, posts need to store the known visibility and use it when federating. a reply to a followers-only post would federate as followers-only.

intended semantics

the semantics is so my followers can see what ppl are saying about my posts, even followers-only posts.

unanswered questions

• what if someone changes visibility?