🐛 fix(payment): add signature type validation

- add validation for supported signature types ['RSA', 'HMAC-SHA256']
- return error when using unsupported signature types

mini/src/utils/payment.ts

@@ -187,6 +187,12 @@ export const validatePaymentSecurity = (
     return { valid: false, reason: '签名类型不能为空' }
   }
 
+  // 验证签名类型是否支持
+  const supportedSignTypes = ['RSA', 'HMAC-SHA256']
+  if (!supportedSignTypes.includes(paymentParams.signType)) {
+    return { valid: false, reason: '签名类型不支持' }
+  }
+
   // 预支付ID格式验证 - 放宽限制以适应微信支付实际返回
   if (!paymentParams.package) {
     return { valid: false, reason: '预支付ID不能为空' }