LINDA SO and GRANT SMITH FROM his jail cell, Chinedu Efoagui sent a plea. "I'm innocent," he wrote his lawyer. "Have all the charges dropped." Born in Nigeria, Efoagui, 38, had been declared a gifted student by the Ministry of Education. He earned a master's degree in computer science and won the visa lottery in 2012, securing a legal path to the United States, where he became a software programmer. "It was a dream come true," said his sister Chioma. He had never been in trouble with the law when he was arrested in 2016 in Georgia after a bizarre…