修复(#84): 补齐促销管理API实现文件

Co-authored-by: multica-agent <github@multica.ai>

ppanel.api

@@ -31,6 +31,7 @@ import (
 	"apis/admin/marketing.api"
 	"apis/admin/application.api"
 	"apis/admin/group.api"
+	"apis/admin/promo.api"
 	"apis/public/user.api"
 	"apis/public/subscribe.api"
 	"apis/public/redemption.api"
@@ -44,4 +45,3 @@ import (
 	"apis/public/portal.api"
 	"apis/public/iap.api"
 )
-