From multi-million-dollar apartments to Antarctic itineraries, life aboard this privately owned ship is built on community.The World, a private residential yacht that offers residences at sea.Credit: The World, Residences at SeaIt’s late afternoon at Quantum sports bar on deck five of The World and crisply dressed residents are filing in for afternoon cocktails and canapés. Irish-born Gary arrives and, moments after we’ve met, offers to buy me a…