Whats the difference between variables {{event.preview}} and {{conversation.SummaryAgent.transcript}} I saw toturial from Robert and Patric that they are using {{conversation.SummaryAgent.transcript}} in their ai task input. I faced problem yesterday that chatbot was repeting the text from the user. Then i switched to {{event.preview}} and it worked smoothley. Can someoone explain the role of these varibles and how i can send from user raw input from one card node to another card norde that uses ai task?