org.passingreads.book.rejectGift

Turn down a gift offered to the authenticated user, so it stops appearing in their account state. Deliberately appview-side only: nothing is written to the recipient's repository and the giver is never told, because a gift is an unsolicited message and being able to refuse one must not expose the refusal. The book never left the giver's hands, so refusing only hides the offer — there is nothing to hand back.