init: hgmj server initial commit

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

app/service/activityclient/client.go

@@ -0,0 +1,7 @@
+package activityclient
+
+// Start 启动活动服客户端的所有定时同步任务（域名 + 红包场次等）
+func Start() {
+	startDomainSync()
+	startHongbaoSync()
+}