add configurable "drop old posts" setting
The title may be confusing, but consider the following:
- an instance is created, and you follow someone that has posts from before the instance was created
- a post from before instance creation makes its way to the instance (via a delete of a reblog, or some other way to reference the post, likes included)
- instance gets the delete activity, fetches the post referencing it, and now the instance has some N months old post appearing as a new one on all timelines
while that may be preffered behavior by default (as for example if an instance goes down for a while and its posts refederate), it can be annoying to think a post was made right now, like it, and then discover it was made 7 months ago because of something being federated back to you that wasn't the direct post.
I tried fixing this with an MRF (with a configurable amount of days to drop posts with) but I'm not fluent on understanding AS2 and gave up on writing it. This could also be something FE-specific where they filter incoming posts that are X months old, but then you also need to account for the mobile clients...