AP blueprints (activitypub.py, ap_social.py) were querying federation
tables (ap_actor_profiles etc.) on g.s which points to the app's own DB
after the per-app split. Now uses g._ap_s backed by get_federation_session()
for non-federation apps.
Also hardens Ghost sync before_app_serving to catch/rollback on failure
instead of crashing the Hypercorn worker.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
