统一的实时金融行情数据API，覆盖外汇、贵金属、指数、美股、港股、A股和加密货币，支持 WebSocket 实时推送与 REST 接口访问 | Unified real-time market data API covering forex, commodities, indices, US stocks, HK stocks, A-shares and cryptocurrencies, with WebSocket streaming and REST access