SEATTLE — As Nneka Ogwumike and Skylar Diggins-Smith sat side-by-side Monday morning at the Seattle Storm Champions Center, the Space Needle loomed from the window to their left. While Seattle’s star signings spoke, the needle’s golden elevator traveled the same 41-second, 520-foot track. Up. Down. Up. Down. The Storm, of course, are familiar with the view both from the ground floor and the observation deck. One’s a whole lot easier on the eyes. To date, Seattle has spent considerably more time at the top — with 18 playoff appearances, 14 winning seasons and four WNBA championships in 24 years…