Do I need a barcode scanner for stock?

No. There is nothing to scan in stock. A dish count is a number you type on Menu → Inventory, an ingredient count is a number you type in the Stock-take panel, and a delivery is received by typing what came beside each line of the purchase order. A phone in the store cupboard is the only equipment. If you are choosing inventory software for restaurants and being asked to buy scanners and labels first, that is a sign the tool was built for a warehouse.