MANILA—Philippine Vice President Leni Robredo, a staunch critic of President Rodrigo Duterte’s brutal war on drugs, joined the race for president on Thursday, promising to usher in a government that cares for the people, not personal interests. Robredo, 56, who was elected separately from Duterte and was not his running mate, said her decision was a difficult one but she wanted to be of greater service to a country facing unprecedented health and economic shocks. “If we truly want to liberate ourselves from this situation, we should change not just the surnames of those in power; the corruption, the incompetence, the lack of compassion must be replaced by competence and integrity in leadership,” said Robredo, who is running as independent candidate. Robredo will face at least four other candidates who have made their presidential runs official, including the son and namesake of the late dictator Ferdinand Marcos, whom she beat …