Version: 0.9.69.dev.260504

后端：
1. 阶段 4 active-scheduler 服务边界落地，新增 `cmd/active-scheduler`、`services/active_scheduler`、`shared/contracts/activescheduler` 和 active-scheduler port，迁移 dry-run、trigger、preview、confirm zrpc 能力
2. active-scheduler outbox consumer、relay、retry loop 和 due job scanner 迁入独立服务入口，gateway `/active-schedule/*` 改为通过 zrpc client 调用
3. gateway 目录收口为 `gateway/api` + `gateway/client`，统一归档 userauth、notification、active-scheduler 的 HTTP 门面和 zrpc client
4. 将旧 `backend/active_scheduler` 领域核心下沉到 `services/active_scheduler/core`，清退旧根目录活跃实现，并补充 active-scheduler 启动期跨域依赖表检查
5. 调整单体启动与 outbox 归属，`cmd/all` 不再启动 active-scheduler workflow、scanner 或 handler

文档：
1. 更新微服务迁移计划，将阶段 4 active-scheduler 标记为首轮收口完成，并明确下一阶段进入 schedule / task / course / task-class

backend/gateway/router/router.go

@@ -7,10 +7,10 @@ import (
 	"net/http"
 	"time"
 
-	"github.com/LoveLosita/smartflow/backend/api"
 	"github.com/LoveLosita/smartflow/backend/dao"
+	"github.com/LoveLosita/smartflow/backend/gateway/api"
+	userauthapi "github.com/LoveLosita/smartflow/backend/gateway/api/userauth"
 	gatewaymiddleware "github.com/LoveLosita/smartflow/backend/gateway/middleware"
-	"github.com/LoveLosita/smartflow/backend/gateway/userapi"
 	rootmiddleware "github.com/LoveLosita/smartflow/backend/middleware"
 	"github.com/LoveLosita/smartflow/backend/pkg"
 	"github.com/LoveLosita/smartflow/backend/shared/ports"
@@ -66,7 +66,7 @@ func RegisterRouters(handlers *api.ApiHandlers, authClient ports.UserAuthClient,
 			})
 		})
 
-		userapi.RegisterRoutes(apiGroup, userapi.NewUserHandler(authClient), authClient, limiter)
+		userauthapi.RegisterRoutes(apiGroup, userauthapi.NewUserHandler(authClient), authClient, limiter)
 
 		taskGroup := apiGroup.Group("/task")
 		{