Shein, the Singapore-based e-commerce and fast-fashion giant, will open an office in downtown Bellevue, Washington, the company said Wednesday, marking some good news for Bellevue’s uneven office market. The nearly 10,000-square-foot office at Key Center will serve as a hub for Shein’s U.S. fulfillment and logistics operations as the retailer seeks to localize and speed up delivery times for U.S. customers. One of the fastest-growing fashion retailers in the world, Shein’s Seattle-area office is the latest step in the company’s U.S. expansion. The company, which has drawn criticism for its lab…