Retrieves the list of free items currently held by a customer within a specific loyalty program. It takes a user identifier and a loyalty program identifier as parameters. It queries the database to find items associated with the user's freebies and the specified loyalty program. It ensures that only active freebies are considered. Moreover, it eagerly loads additional information such as the details of the freebie and the merchant offering it. Finally, it maps the retrieved freebies and returns the result.