In the ongoing human pursuit of devices that collapse the boundary between pocket and canvas, Huawei has unveiled the Mate XT 2 Ultimate Design — a tri-fold phone that quietly acknowledges a rival's wisdom by adopting an inward-folding hinge where its predecessor folded outward. Priced between $2,945 and $4,500 and available only in China for now, it represents less a product for the masses than a philosophical claim about what mobile technology can aspire to become. With Samsung having stepped back from the tri-fold arena, Huawei stands at an unusual crossroads: the inheritor of a category it