NEW YORK — For nearly a year, Shahed Hussain would slip into his role as a wealthy Pakistani businessman and head for Newburgh. He was “Maqsood” when he arrived at local mosque Masjid Al-Ikhlas driving a BMW, or maybe Hummer depending on the day. He was there to listen for Islamic extremism and report back to the FBI, he said. Hussain testified on Friday in the federal trial of four Newburgh men accused of trying to shoot down planes at Stewart Air National Guard Base and blow up a synagogue and Jewish center in the Bronx. The men — James...