The winner of an online charity fundraiser — a 4-inch-tall version of the top bidder, that is — will get to live in this Coronado Craftsman-style home built at Legoland California. “It’s the only way most San Diegans can afford a beach home,” joked Julie Estrada, director of public relations, North America, for Merlin Entertainments, the owner of Legoland. “You’re …