Before I get sucked into writing my own... is there a light weight 'turn this site into an #activitypub' project out there already? Basically, add it to a static site and it treats all urls from that site (except the activity pub end points) as articles written by a user called @[email protected] or something similar. Bonus points for a little embed script that displays replies to the pages on the pages.
Something driven by an #rss feed could work as well?