Remove one receipt item

What your assistant is told

Remove ONE line from a receipt — a line that was misread, or something the user did not actually buy. itemId is the item's UUID from get_receipt. The receipt itself stays, and what the line covered goes back into the transaction's own category as "Not itemised", so the split still equals the payment and no money disappears. This cannot be undone from here — confirm with the user first. Returns the receipt as it now stands. To correct a line rather than remove it use update_receipt_item; to drop the whole receipt use delete_receipt.