A Florida jury yesterday ruled against the tobacco industry in the first class-action lawsuit by six smokers to come to trial, finding that cigarette makers addicted and defrauded smokers and could be forced to pay billions of dollars in damages. In the broadest ruling to date in the legal war over tobacco, the Miami jury concluded that cigarette makers “engaged in extreme and outrageous conduct,” concealing cigarettes’ dangers, conspiring to hide their addictiveness, and making a product that caused more than a dozen deadly diseases, from heart disease to lung cancer.