feat: Sort contacts via name, email, phone_number, last_activity_at (#1870)

app/models/message.rb

@@ -133,6 +133,11 @@ class Message < ApplicationRecord
     dispatch_create_events
     send_reply
     execute_message_template_hooks
+    update_contact_activity
+  end
+
+  def update_contact_activity
+    sender.update(last_activity_at: DateTime.now) if sender&.is_a?(Contact)
   end
 
   def dispatch_create_events