china-bankcard
中国银行卡号解析与验证。Use when the user provides a Chinese bank card number and wants to identify the issuing bank, card type (借记卡/信用卡), card organization (银联/Visa/MasterCard/AmEx/JCB), card length, or validate the Luhn checksum. Covers top 20 Chinese banks. Fully offline — no network, no API key required.