Enriching webmentions from third-party platforms

I keep finding new gaps in my webmention implementation. Mentions coming in from Bluesky, Lemmy and Lobsters were showing up with no author at all, just a blank avatar and an empty name. Reddit and Hacker News bookmarks fared a bit better, with a username attached, but got flattened into a generic “bookmarked” icon with no indication of where the post had actually been shared. Lobsters mentions…