DETROIT — The prosecution next month of four men accused of plotting to kidnap Michigan Gov. Gretchen Whitmer will be a multimedia production with testimony from four dozen witnesses, a replica bomb built by the FBI, virtual recreations of key locations, including a secret training camp, and a discrete plan to compensate for scandals engulfing the case. Federal prosecutors sketched a broad trial outline in a court filing Thursday that provided a detailed view of a closely watched case that has shed light on violent extremism in Michigan. The case has coincided with a rise in political violence…