Only share public statuses.

Only actually public, i.e. not "unlisted". One exception: Share
an update if the update changed the visibility from "public" to
something else. The fasp can act on this information then.

app/models/concerns/status/fasp_concern.rb

@@ -13,20 +13,20 @@ module Status::FaspConcern
   private
 
   def announce_new_content_to_subscribed_fasp
-    return unless account_indexable?
+    return unless account_indexable? && public_visibility?
 
     store_uri unless uri # TODO: solve this more elegantly
     Fasp::AnnounceContentLifecycleEventWorker.perform_async(uri, 'new')
   end
 
   def announce_updated_content_to_subscribed_fasp
-    return unless account_indexable?
+    return unless account_indexable? && public_visibility_or_just_changed?
 
     Fasp::AnnounceContentLifecycleEventWorker.perform_async(uri, 'update')
   end
 
   def announce_deleted_content_to_subscribed_fasp
-    return unless account_indexable?
+    return unless account_indexable? && public_visibility?
 
     Fasp::AnnounceContentLifecycleEventWorker.perform_async(uri, 'delete')
   end
@@ -42,4 +42,8 @@ module Status::FaspConcern
       end
     Fasp::AnnounceTrendWorker.perform_async(candidate_id, trend_source) if candidate_id
   end
+
+  def public_visibility_or_just_changed?
+    public_visibility? || visibility_previously_was == 'public'
+  end
 end