after 30 days, replace comment.content and post.body with 'Deleted'

[vijaykramesh]

fixes #2977

on server startup, and then with a daily scheduler thread -

check for all posts & comments where deleted = true && updated < 30 days ago && body/content != "Deleted" and sets it to "Deleted"

this way deletes for comments & posts get federated after 30 days by default.

[Nutomic]

You have some conflicts, need to rebase with latest main branch.