Of all the legal cases that former President Donald J. Trump is facing, perhaps the most personal is playing out in a courtroom in Manhattan: a civil fraud trial that could result in him losing control of his best-known buildings and paying hundreds of millions of dollars in fines. In recent days, Mr. Trump and some of his children have taken the stand, defending the family business and the former president’s reputation as a real-estate mogul. Jonah E. Bromwich, who covers justice in New York for The Times, was inside the courtroom.