docs: show ZPay URL explicitly in parentheses

docs/PAYMENT.md

@@ -28,7 +28,7 @@ Sub2API has a built-in payment system that enables user self-service top-up with
 
 > Alipay/WeChat Pay direct and EasyPay can coexist. Direct channels connect to payment APIs directly with lower fees; EasyPay aggregates through third-party platforms with easier setup.
 
-> **EasyPay Recommendation**: [ZPay](https://z-pay.cn/?uid=23808) is recommended as an EasyPay provider (link contains the author's referral code — feel free to remove it). ZPay supports **individual users** (no business license required) with up to 10,000 CNY daily transactions; business-licensed accounts have no limit. Please evaluate the security, reliability, and compliance of any third-party payment provider on your own — this project does not endorse or guarantee any of them.
+> **EasyPay Recommendation**: [ZPay](https://z-pay.cn/?uid=23808) (`https://z-pay.cn/?uid=23808`) is recommended as an EasyPay provider (link contains the author's referral code — feel free to remove it). ZPay supports **individual users** (no business license required) with up to 10,000 CNY daily transactions; business-licensed accounts have no limit. Please evaluate the security, reliability, and compliance of any third-party payment provider on your own — this project does not endorse or guarantee any of them.
 
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docs/PAYMENT_CN.md

@@ -28,7 +28,7 @@ Sub2API 内置支付系统，支持用户自助充值，无需部署独立的支
 
 > 支付宝官方 / 微信官方与 EasyPay 可以共存。官方渠道直接对接 API，资金直达商户账户，手续费更低；EasyPay 通过第三方平台聚合，接入门槛更低。
 
-> **EasyPay 推荐**：个人推荐 [ZPay](https://z-pay.cn/?uid=23808) 作为 EasyPay 服务商（链接含作者邀请码，介意可去掉）。ZPay 支持**个人用户**（无营业执照）每日 1 万元以内交易；拥有营业执照则无限额。支付渠道的安全性、稳定性及合规性请自行鉴别，本项目不对任何第三方支付服务商做担保或背书。
+> **EasyPay 推荐**：个人推荐 [ZPay](https://z-pay.cn/?uid=23808)（`https://z-pay.cn/?uid=23808`）作为 EasyPay 服务商（链接含作者邀请码，介意可去掉）。ZPay 支持**个人用户**（无营业执照）每日 1 万元以内交易；拥有营业执照则无限额。支付渠道的安全性、稳定性及合规性请自行鉴别，本项目不对任何第三方支付服务商做担保或背书。
 
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