Version: 0.9.71.dev.260504

后端：
1.阶段 5 task 服务边界落地
- 新增 cmd/task 与 services/task/{dao,rpc,sv}，承载 task zrpc、tasks 表迁移和 task outbox 消费边界
- 新增 gateway/client/task、shared/contracts/task 和 task port，gateway /api/v1/task/* 切到 task zrpc client
- 将 task.urgency.promote.requested handler / relay / retry loop 迁入 cmd/task，单体 worker 不再消费 task outbox
- 保留单体 Agent 残留 task 查询的 publish-only 写入能力，避免迁移期 task 事件丢失
- active-scheduler task facts / due job scanner 切到 task RPC，并移除启动期 tasks 表依赖检查
- 更新阶段 5 文档，记录 task 切流点、旧实现保留、跨域 DB 依赖缩减和下一轮建议
- 补充 task rpc 示例配置

backend/gateway/client/task/client.go

@@ -0,0 +1,149 @@
+package task
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"strings"
+	"time"
+
+	taskpb "github.com/LoveLosita/smartflow/backend/services/task/rpc/pb"
+	taskcontracts "github.com/LoveLosita/smartflow/backend/shared/contracts/task"
+	"github.com/zeromicro/go-zero/zrpc"
+	"google.golang.org/grpc"
+)
+
+const (
+	defaultEndpoint = "127.0.0.1:9085"
+	defaultTimeout  = 6 * time.Second
+)
+
+type ClientConfig struct {
+	Endpoints []string
+	Target    string
+	Timeout   time.Duration
+}
+
+// Client 是 gateway 侧 task zrpc 的最小适配层。
+//
+// 职责边界：
+// 1. 只负责跨进程 gRPC 调用和 JSON 透传，不碰 DAO、outbox 或 active-scheduler job；
+// 2. HTTP 入参仍由 gateway/api 做基础绑定，业务校验交给 task 服务；
+// 3. 复杂响应不在 gateway 重建模型，避免 DTO 复制扩散。
+type Client struct {
+	rpc taskpb.TaskClient
+}
+
+func NewClient(cfg ClientConfig) (*Client, error) {
+	timeout := cfg.Timeout
+	if timeout <= 0 {
+		timeout = defaultTimeout
+	}
+	endpoints := normalizeEndpoints(cfg.Endpoints)
+	target := strings.TrimSpace(cfg.Target)
+	if len(endpoints) == 0 && target == "" {
+		endpoints = []string{defaultEndpoint}
+	}
+
+	zclient, err := zrpc.NewClient(zrpc.RpcClientConf{
+		Endpoints: endpoints,
+		Target:    target,
+		NonBlock:  true,
+		Timeout:   int64(timeout / time.Millisecond),
+	})
+	if err != nil {
+		return nil, err
+	}
+	client := &Client{rpc: taskpb.NewTaskClient(zclient.Conn())}
+	if err := client.ping(timeout); err != nil {
+		return nil, err
+	}
+	return client, nil
+}
+
+func (c *Client) AddTask(ctx context.Context, req taskcontracts.AddTaskRequest) (json.RawMessage, error) {
+	resp, err := c.callJSON(ctx, c.rpc.AddTask, req)
+	return jsonFromResponse(resp, err)
+}
+
+func (c *Client) GetUserTasks(ctx context.Context, userID int) (json.RawMessage, error) {
+	resp, err := c.callJSON(ctx, c.rpc.GetUserTasks, taskcontracts.UserRequest{UserID: userID})
+	return jsonFromResponse(resp, err)
+}
+
+func (c *Client) BatchTaskStatus(ctx context.Context, req taskcontracts.BatchTaskStatusRequest) (json.RawMessage, error) {
+	resp, err := c.callJSON(ctx, c.rpc.BatchTaskStatus, req)
+	return jsonFromResponse(resp, err)
+}
+
+func (c *Client) CompleteTask(ctx context.Context, req taskcontracts.CompleteTaskRequest) (json.RawMessage, error) {
+	resp, err := c.callJSON(ctx, c.rpc.CompleteTask, req)
+	return jsonFromResponse(resp, err)
+}
+
+func (c *Client) UndoCompleteTask(ctx context.Context, req taskcontracts.UndoCompleteTaskRequest) (json.RawMessage, error) {
+	resp, err := c.callJSON(ctx, c.rpc.UndoCompleteTask, req)
+	return jsonFromResponse(resp, err)
+}
+
+func (c *Client) UpdateTask(ctx context.Context, req taskcontracts.UpdateTaskRequest) (json.RawMessage, error) {
+	resp, err := c.callJSON(ctx, c.rpc.UpdateTask, req)
+	return jsonFromResponse(resp, err)
+}
+
+func (c *Client) DeleteTask(ctx context.Context, req taskcontracts.DeleteTaskRequest) (json.RawMessage, error) {
+	resp, err := c.callJSON(ctx, c.rpc.DeleteTask, req)
+	return jsonFromResponse(resp, err)
+}
+
+func (c *Client) ensureReady() error {
+	if c == nil || c.rpc == nil {
+		return errors.New("task zrpc client is not initialized")
+	}
+	return nil
+}
+
+func (c *Client) ping(timeout time.Duration) error {
+	if err := c.ensureReady(); err != nil {
+		return err
+	}
+	ctx, cancel := context.WithTimeout(context.Background(), timeout)
+	defer cancel()
+	_, err := c.rpc.Ping(ctx, &taskpb.StatusResponse{})
+	return responseFromRPCError(err)
+}
+
+func (c *Client) callJSON(ctx context.Context, fn func(context.Context, *taskpb.JSONRequest, ...grpc.CallOption) (*taskpb.JSONResponse, error), payload any) (*taskpb.JSONResponse, error) {
+	if err := c.ensureReady(); err != nil {
+		return nil, err
+	}
+	raw, err := json.Marshal(payload)
+	if err != nil {
+		return nil, err
+	}
+	return fn(ctx, &taskpb.JSONRequest{PayloadJson: raw})
+}
+
+func jsonFromResponse(resp *taskpb.JSONResponse, rpcErr error) (json.RawMessage, error) {
+	if rpcErr != nil {
+		return nil, responseFromRPCError(rpcErr)
+	}
+	if resp == nil {
+		return nil, errors.New("task zrpc service returned empty JSON response")
+	}
+	if len(resp.DataJson) == 0 {
+		return json.RawMessage("null"), nil
+	}
+	return json.RawMessage(resp.DataJson), nil
+}
+
+func normalizeEndpoints(values []string) []string {
+	endpoints := make([]string, 0, len(values))
+	for _, value := range values {
+		trimmed := strings.TrimSpace(value)
+		if trimmed != "" {
+			endpoints = append(endpoints, trimmed)
+		}
+	}
+	return endpoints
+}