BOSTON — Field hockey at Harvard Stadium. Fencing and archery at MIT. Horses for the equestrian events cared for at the Tufts Hospital for Large Animals.Welcome to the University Games.Boston is bidding on the 2024 Summer Olympics, and the crux of its proposal is a walkable, sustainable, technology-based event that would harness the resources of the Boston area's 100 colleges and universities to keep the Games affordable and compact.