feat: 从黄果 NET hgdjnet-server 9bfbafe 导入 HKDJ 官网后端

来源：hgdjnet-server 9bfbafe10d417deea959bd53117bc88a10e60a83
项目身份 HKDJ / JHA-216，独立官网仓库，Jenkins 守卫键 hkdjnet
测试目录 /server/hkdj_net，App/Web API 30331/30332

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

web/router/third.go

@@ -0,0 +1,17 @@
+package router
+
+import (
+	"hkdj-web-server/web/api/web_recharge"
+
+	"github.com/gin-gonic/gin"
+)
+
+func thirdRouter(r *gin.Engine) {
+	thirdGroup := r.Group("/api/web/third")
+	{
+		paycenterGroup := thirdGroup.Group("/paycenter")
+		{
+			paycenterGroup.POST("/bill/callback", web_recharge.PayCenterBillCallback)
+		}
+	}
+}