By Ricardo Brito and Rodrigo Viga Gaier BRASILIA (Reuters) – Brazil’s electoral authorities are preparing for a competitive election on Sunday with a result that may be contested by far-right President Jair Bolsonaro if he loses to his leftist adversary, who has a narrow lead in recent opinion polls. Brazil’s Superior Electoral Court (TSE), led by justices from the Supreme Court, is ready for Bolsonaro to dispute any victory by former President Luiz Inacio Lula da Silva, potentially mobilizing angry demonstrations, according to people familiar with the court’s preparations who requested anonym…