feat: 分俱乐部付呗收款通道，默认仍走微信直连

小程序前端仍传 wechat；后台可切换 wechat/fubei，支持配置多套付呗并退款按原通道路由。

Co-authored-by: Cursor <cursoragent@cursor.com>

users/views/kefu_orders.py

@@ -858,6 +858,16 @@ class KefuPlatformRefundView(APIView):
         :param transaction_id: 微信支付订单号（优先使用）
         :return: {'code': 0, 'msg': '成功', 'refund_id': 'xxx'} 或 {'code': 非0, 'msg': '错误信息'}
         """
+        from jituan.services.pay_refund_router import try_fubei_refund
+        from jituan.services.wechat_pay import club_id_from_order
+        fb = try_fubei_refund(
+            out_trade_no=dingdan_id,
+            amount_yuan=jine,
+            club_id=club_id_from_order(dingdan_id),
+        )
+        if fb is not None:
+            return fb
+
         # 获取配置
         appid = getattr(settings, 'WEIXIN_APPID', '')
         mch_id = getattr(settings, 'WEIXIN_MCHID', '')