── 取值来源（不含密钥值）──
  base-url                 = https://test.gdyfsk.com/yfpay   [application.yml 字面量]
  inst-no                  = 900112             [application.yml 默认值（键 LESHOUYING_INST_NO）]
  key                      = <len=32>        [application.yml 默认值（键 LESHOUYING_KEY）]
  default-qr-expire-minutes= 15            [取自 application.yml]

── 将发送（不含密钥；sign 打码）──
  A = inst_no=900112&mch_no=Y52211090004&order_body=联调探针-主扫&pay_time=20260928152205&pay_trace_no=probe20260928152205qr&time_expire=15&total_amount=1

  body = {
  "inst_no": "900112",
  "mch_no": "Y52211090004",
  "pay_trace_no": "probe20260928152205qr",
  "pay_time": "20260928152205",
  "total_amount": "1",
  "time_expire": "15",
  "order_body": "联调探针-主扫",
  "sign": "<len=32>"
}

  字段清单（= 生产 createQrOrder 发的集合）：inst_no, mch_no, order_body, pay_time, pay_trace_no, sign, time_expire, total_amount

── 出站 ──
  POST https://test.gdyfsk.com/yfpay/v3/qrpay
  Content-Type: application/json;charset=utf-8
  bytes = 241

── 上游应答 ──
  http_code = 200
  bytes     = 370
  原始字节已落 logs/_lsy-qrpay-resp.bin

  解码 = utf-8 成功
  return_code = SUCCESS
  return_msg  = 聚合码请求成功！
  result_code = PAY_SUCCESS
  code_url    = https://test.gdyfsk.com/yfpay/s/s-00002

── 入站验签（null 不参与）──
  参与签名的字段数 = 11 / 应答字段数 11
  A = code_url=https://test.gdyfsk.com/yfpay/s/s-00002&mch_name=建行小店基本休息修改&mch_no=Y52211090004&pay_time=20260928152205&pay_trace_no=probe20260928152205qr&result_code=PAY_SUCCESS&return_code=SUCCESS&return_msg=聚合码请求成功！&shop_name=&shop_no=&total_amount=1
  重算 == 上游 sign : True