If there was ever any doubt about who should be recognized as the greatest artist the Bay Area ever produced, the San Francisco Museum of Modern Art has resolved the question definitively with its lovingly presented, sweeping analysis of the work of Bruce Conner. The exhibition “It’s All True,” opening Saturday, Oct. 29, comprises some 300 works and is accompanied by an authoritative, 384-page book. Together, show and catalog provide a detailed argument for the artist’s dominance in a range of media, from collage and assemblage, to independent film, to conceptual art.