feat(config): 新增配置回收站与还原功能

- 配置列表支持 deleted=1 查询已删除配置
- 新增 POST /admin/config/restore/:id，还原配置并写入 restore 历史
- 前端新增回收站页面，配置列表「新建配置」右侧增加红色入口按钮

server/cmd/main.go

@@ -66,6 +66,7 @@ func main() {
 		admin.POST("/config/add", configHandler.Add)
 		admin.POST("/config/update", configHandler.Update)
 		admin.POST("/config/delete/:id", configHandler.Delete)
+		admin.POST("/config/restore/:id", configHandler.Restore)
 		admin.GET("/config/configHistories/:id", configHandler.GetHistory)
 		admin.POST("/config/history/delete/:id", configHandler.DeleteHistory)
 		admin.POST("/config/rollback/:id", configHandler.Rollback)