The Biden administration is set to approve plans for the first major offshore wind farm in federal waters, according to two people familiar with the matter. The Interior Department authorization, which could come as soon as Tuesday, will pave the way for construction of the 800-megawatt Vineyard Wind LLC project near the coast of Massachusetts, and puts it on a path to begin supplying power to some 400,000 East Coast homes late next year. The agency’s plans were described by people familiar with the matter who asked not to be named before a formal announcement.