The Giants finally introduced prized new third baseman Evan Longoria on Friday, a month after acquiring the longtime Tampa Bay star in a blockbuster deal. First things first: Longoria will wear No. 10 for the Giants. His former No. 3 was not available — that belongs to former Giants player/manager Bill Terry, whose number is among the 10 retired in franchise history. Longoria spoke to season-ticket holders before Friday’s news conference at AT&T Park, and said Giants fans were most curious about Longoria’s views on where he fits into a veteran clubhouse that counts Buster Posey and Madison Bumgarner among its faces of the franchise.