Add conversation-based forwarding for limited visibility statuses through bearcaps

app/serializers/activitypub/note_serializer.rb

@@ -7,7 +7,7 @@ class ActivityPub::NoteSerializer < ActivityPub::Serializer
              :in_reply_to, :published, :url,
              :attributed_to, :to, :cc, :sensitive,
              :atom_uri, :in_reply_to_atom_uri,
-             :conversation
+             :conversation, :context
 
   attribute :content
   attribute :content_map, if: :language?
@@ -121,6 +121,12 @@ class ActivityPub::NoteSerializer < ActivityPub::Serializer
     end
   end
 
+  def context
+    return if object.conversation.nil?
+
+    ActivityPub::TagManager.instance.uri_for(object.conversation)
+  end
+
   def local?
     object.account.local?
   end