Detect the card network and tier (Visa, Mastercard, UnionPay and more) from the number prefix, entirely offline.
信用卡型別檢測。根據卡號字首(BIN)識別髮卡組織與卡等級(如 Visa/Master/銀聯),用於表單校驗與支付前端判斷,純前端檢測不聯網。