EventTrigger - Payload Transform

### Version Information

Server Version: v2.8.1-cloud.1
CLI Version (for CLI related issue):

### Environment

Cloud

### What is the expected behaviour?

I want to access {{$body.event.data.old?.content}}

But on insert event, there is an error on processed events

I think it's normal because {{$body.event.data.old.content}} not exists on insert. But i want to use this syntax Kriti with '?' in order to prevent the error field access.

Thanks !

No source file or test is named. Begin with the EventTrigger payload-transform path and the Kriti expression shown in the issue; done means an insert event can evaluate the missing old.content access without producing a processed-event error.

Written by the indexing model from the issue text.