Sen. Dianne Feinstein and her mega-millionaire husband, Richard Blum, are pulling up stakes on their quiet Presidio Terrace home and moving uptown to a Pacific Heights mansion -- with views to die for. The $16.5 million mansion -- which sits at the foot of Vallejo Street, between the Presidio and some of the city's most hoity-toity addresses -- offers a sweeping view of the bay. It's right off what Herb Caen christened the "Gold Rush" -- the final two blocks of upper, upper Broadway, where the residents include Ann and Gordon Getty, Oracle founder Larry Ellison, and Mimi Haas...