Huawei Technologies Co. is nearing a deal to let Tencent Holdings Ltd.’s WeChat super app operate fully on its Harmony mobile platform without sharing any revenue, a concession designed to defend its newfound lead over Apple Inc. in China.The deal, in which Huawei will agree not to charge Tencent any fee for in-app transactions within the WeChat universe, comes after months-long negotiations between the two Shenzhen-based tech behemoths, according to people with knowledge of the matter. They dec...