By Eduardo Baptista BEIJING (Reuters) -When Eileen Gu won Olympic gold in the Big Air, sales of her red Anta ski suit, complete with slipdrag reduction technology, surged 20-fold on Chinese e-commerce platform JD.com. Luckin Coffee sold out of Gu-endorsed drinks, with a spike in cup-holders bearing her image, and the Chinese chain immediately said it would launch more Gu-linked products throughout the year. The San Francisco-born skier won a silver medal in Tuesday’s slopestyle final, earning more praise on Chinese social media for redeeming herself on a third jump after an earlier mistake. Wi…