How do the shops even work if there are no employees managing the shops? Is it like a vending machine? Is there magic that prevents people from just taking stuff? What about restocking? Where do the items come from? Does it just magically reappear when someone pays? What if no one pays, do product never appear again? I'm really confused about how the shops are supposed to work there...
the shops function with a self check out since that's how it was shown when he first summoned the SS Fortress ship,
he bought some snacks and the girls did too.
it's probably easy to assume that if someone doesn't buy something there's an alarm type situation like you'd expect from IRL shops with anti theft alarms (just better/accurate since it's magic), also assuming that items that are stolen can't be taken off the ship too since people require permission to enter it's easy to believe that someone can't steal stuff without being blocked from leaving the ship or blocked from taking the item off at least.
since he's buying basically fully furnished ships the items and even furniture etc... everything is there from the beginning, either he might have to resummon the ship for items to restock (essentially resetting it) or maybe they do just restock over time because magic.