Hong Kong CNN  —  A surprise breakthrough in US-China trade tensions has unleashed a flurry of activity across Chinese factories and ports as American and Chinese companies rush to make the most of a 90-day rollback of heavy tariffs announced earlier this week. For Niki Ye, a salesperson in southern China who sources toys for sale on Amazon, a 30% spike in orders since that announcement has meant her company is staffing up to meet demand. “And this is only the first week,” she said. Liu