Fix default assumed object type (note->activity), make stream entry threaded? check aware of orphaned replies

app/models/stream_entry.rb

@@ -39,7 +39,7 @@ class StreamEntry < ApplicationRecord
   end
 
   def threaded?
-    verb == :favorite || object_type == :comment
+    (verb == :favorite || object_type == :comment) && !thread.nil?
   end
 
   def thread

app/services/process_feed_service.rb

@@ -214,7 +214,7 @@ class ProcessFeedService < BaseService
   def object_type(xml)
     xml.at_xpath('./activity:object-type').content.gsub('http://activitystrea.ms/schema/1.0/', '').to_sym
   rescue
-    :note
+    :activity
   end
 
   def verb(xml)