This is the big one. - Need to teach it how to use a furnace, or other machinery. - These should be abstracted so other programs can be slotted in. - e.g. a 'vanilla_furnace' program that takes the `furnace` recipes, and manages moving items into a furnace and pulling them back out. - Then being able to swap it for a 'create furnace' that deposits items into a chest/chute, and then polls for items turning up in bulk storage.