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>

shop/views/shop_refund_views.py

@@ -200,6 +200,15 @@ class ShopRefundView(APIView):
     # ========== 微信退款 ==========
     def _call_wechat_refund(self, order):
         """调用微信支付退款接口"""
+        from jituan.services.pay_refund_router import try_fubei_refund
+        fb = try_fubei_refund(
+            out_trade_no=order.OrderID,
+            amount_yuan=order.Amount or 0,
+            club_id=getattr(order, 'ClubID', None),
+        )
+        if fb is not None:
+            return fb
+
         appid = getattr(settings, 'WEIXIN_APPID', '')
         mch_id = getattr(settings, 'WEIXIN_MCHID', '')
         key = getattr(settings, 'WEIXIN_SHANGHUMIYAO', '')