August Wilson’s spirit looms large in all of his works, but never more so than in this production at the Mark Taper Forum in Los Angeles. “Radio Golf,” which examines the price of success for blacks in the ’90s, is the long-awaited finale of his 10-part dramatic cycle about African American life. The project, which took nearly a quarter-century to complete, is seen as both a masterwork of the theater and a treasure of American social history. Celebration of the cycle’s completion has been tempered by last month’s announcement that the 60-year-old writer is battling liver cancer.”