Display the preorder availability date as a range

Allow merchants to display an availability date range for preorder products, rather than only a single availability date. For example, a merchant should be able to show: “Expected to ship between 10 and 20 August” This would help merchants communicate more realistic fulfilment timelines when the exact availability date is uncertain. The date range should be configurable for each preorder offer, allowing different products or product groups to display their own estimated availability windows.