KAREN FREIFELD and LUC COHEN WORKERS erected barricades around a Manhattan courthouse as New York City braced for a possible indictment of Donald Trump over an alleged hush-money payment to porn star Stormy Daniels during his 2016 campaign. It would be the first-ever criminal case against any U.S. president. On Saturday, Trump urged followers on social media to protest what he said was his looming arrest. In his call for protests, Trump raised concerns for law enforcement that supporters might engage in violence similar to the Jan. 6, 2021, attack on the U.S. Capitol in Washington. Fearing a trap, however,…