A rooftop Gulfstream fuselage has become the latest flashpoint in a wealthy Southern California waterfront community, and one family's giant inflatable replica is making sure no one can miss it. The outsized protest in Coronado Cays has turned what might have remained a niche HOA dispute into a very public fight over what belongs in a residential neighborhood. What happened? Residents in Coronado Cays are pushing back against plans for "Casa Fat…