Route outbound Follow through EventProcessor for retry

send_follow now emits a Follow activity via emit_activity() instead of
inline HTTP POST. New ap_follow_handler delivers to the remote inbox;
EventProcessor retries on failure. Wildcard delivery handler skips
Follow type to avoid duplicate broadcast.

Also add /social/ index page to per-app social blueprint.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

shared/events/handlers/ap_delivery_handler.py

@@ -146,6 +146,9 @@ async def on_any_activity(activity: APActivity, session: AsyncSession) -> None:
         return
     if not services.has("federation"):
         return
+    # Follow activities are delivered by ap_follow_handler, not broadcast
+    if activity.activity_type == "Follow":
+        return
 
     # Load actor with private key
     actor = (