After a merge initiated with isPostMergeDeferred=true reaches MergeCompleted status,
call this endpoint to trigger all post-merge operations (output behavior / DS7 delivery actions,
save copy, activity/task creation, field updates, email, destinations, sign, presign)
and receive the redirect URI.
Salesforce credentials are resolved automatically via CORGI.
Should only be used when isPostMergeDeferred is true