The Kalmar, a drab, three-story floating hotel once used to detain migrants, is towed into the Norwegian village of Glomfjord, sea eagles circling overhead. Its approximately 220 bedrooms are empty in early October, waiting for the arrival of hundreds of construction workers to speed up the buildout of Nscale’s data center, rising on the edge of the fjord.The facility, just north of the Arctic Circle, is billed as a flagship site for the British data-center developer, but construction is six mon...