IPOJUCA, Brazil — More than 40,000 laborers swarm the port complex here in northeast Brazil, building a refinery for the state oil company. Five thousand others toil at a shipyard, another government-led project. Real estate prices are soaring and unemployment is falling in this region along the Atlantic coast, once known for its festering poverty. In a show of the extraordinary sway that Brazil’s government wields in nearly every important area of the economy, President Dilma Rousseff is accelerating an array of stimulus projects throughout the country aimed at blunting a slowdown that has reduced Brazil’s economic growth to a...