OAKLAND, Calif. — The infield is made of asphalt right now. So are the dugouts, the outfield and the stands. Someday this might be home to a baseball stadium, but today the Howard Terminal is little more than a parking lot for 16-wheelers, populated by far more sea gulls than baseball fans. Dave Kaval, the Oakland Athletics‘ team president, walks from the gigantic cranes on the water’s edge to what soon might be the site of home plate. It smells like diesel fuel, not peanuts or Cracker Jacks. He no longer sees this 55-acre plot of land as a desolate storage space along the San Francisco Bay. He can’t afford to focus on what he sees here today or dwell on what the ballpark might look like when it opens its doors. He has to figure out how a stadium might still be serviceable decades down the road. “We’re hopeful we’re going to build a ballpark that’s like a Fenway or Wrigley,” he said, “that will last 100 years.” To do that, the A’s are having to confront a growing list of challenges, many that might not fully present themselves for years to come. The team is determined to build…