Will I be sinful for selling a program to stores that facilitates the sales process, even though it is possible to sell prohibited items such as cigarettes, sweets, intoxicants, nutmeg, and cloves, knowing that I can exclude the sale of prohibited items, but that will make the sales process difficult for the seller? Does my work fall under the rule of "umum al-balwa" (widespread affliction)?

It is advisable to avoid excessive inquiry and investigation into what is unnecessary. If someone develops a program and then offers it for sale, they are not obligated to investigate the type of goods that will be fed into the programs thereafter. However, if the questioner is the one who will prepare the program's database for each store, then they are obligated not to include any forbidden goods, such as tobacco. Also, nutmeg is forbidden, whereas cloves are permissible.