NEW YORK (AP).- The agency building the new World Trade Center says a design flaw could add millions of dollars to the cost of the complex’s signature tower. The Port Authority of New York and New Jersey said Tuesday that the loading dock under One World Trade Center won’t be finished in time for tenants to move their equipment into the 104-story tower. So it’s building five temporary loading bays above ground. A temporary station that was built for the Port Authority Trans Hudson subway is blocking access to the underground loading area. The station can’t be dismantled to make way for underground freight areas until crews finish the permanent station. “Several years ago there was a design miss,” Patrick Foye, executive director of the Port Authority, told reporters Tuesday. “Should it have been caught? The