DeliverEventToIntegration delivers an event to an integration and returns the response.

The event payload to deliver to the integration. Typically the output of TransformEventWithPlaybook, which may have stripped fields like writeKey and type. Use original_event to provide the unmodified client event for metadata derivation.

The unmodified client event. Used to derive writeKey, event name, userId, and other metadata for delivery. When omitted, falls back to event_name (if set) or extraction from input_event.