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/api/web_cfg/protodef.go

@@ -0,0 +1,18 @@
+package web_cfg
+
+import (
+	"hkdj-web-server/pub/models/cfg"
+	"hkdj-web-server/web/service/srv_cfg"
+)
+
+type GetSysConfigReq struct {
+}
+
+type GetSysConfigResp struct {
+	*cfg.SysCfg
+}
+
+type SysConfigUpdateReq struct {
+	srv_cfg.SysCfgUpdate
+}
+type SysConfigUpdateResp struct{}