Mastodon ignored Delete activities because the Tombstone id was the
post URL, not the object id from the original Create activity. Now
looks up the existing Create activity and uses its object id.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Federation activities are now created at write time via try_publish()
instead of relying on async event handlers. Fixes race condition where
multiple EventProcessors could consume post.published events in apps
that couldn't meaningfully process them.
AP delivery (federation.activity_created → inbox POST) stays async.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>