By Anthony Boadle BRASILIA (Reuters) -Brazilian markets delivered a withering verdict on leftist President Luiz Inacio Lula da Silva’s first full day in office on Monday, after he pledged to prioritize social issues and ordered a budget-busting extension to a fuel tax exemption. Lula’s decision to extend the fuel tax exemption, which will deprive the Treasury of 52.9 billion reais ($9.9 billion) a year in fiscal income, was a stinging rebuke of his finance minister Fernando Haddad, a Workers Party (PT) loyalist who had said it would not be extended. Haddad, who is seeking to dispel market fear…