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/services/active_scheduler/core/adapters/task_rpc.go

@@ -0,0 +1,152 @@
+package adapters
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"strings"
+	"time"
+
+	activeports "github.com/LoveLosita/smartflow/backend/services/active_scheduler/core/ports"
+	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/codes"
+	"google.golang.org/grpc/status"
+)
+
+const (
+	defaultTaskRPCEndpoint = "127.0.0.1:9085"
+	defaultTaskRPCTimeout  = 6 * time.Second
+)
+
+type TaskRPCConfig struct {
+	Endpoints []string
+	Target    string
+	Timeout   time.Duration
+}
+
+// TaskRPCAdapter 是 active-scheduler 访问 task 服务的 RPC 适配器。
+//
+// 职责边界：
+// 1. 只读取 task_pool 事实并转换为 active-scheduler 内部 DTO；
+// 2. 不写 tasks 表、不维护 task outbox，也不处理 due job 状态；
+// 3. 让 active-scheduler dry-run / due scanner 不再直接访问 tasks 表。
+type TaskRPCAdapter struct {
+	rpc taskpb.TaskClient
+}
+
+func NewTaskRPCAdapter(cfg TaskRPCConfig) (*TaskRPCAdapter, error) {
+	timeout := cfg.Timeout
+	if timeout <= 0 {
+		timeout = defaultTaskRPCTimeout
+	}
+	endpoints := normalizeTaskRPCEndpoints(cfg.Endpoints)
+	target := strings.TrimSpace(cfg.Target)
+	if len(endpoints) == 0 && target == "" {
+		endpoints = []string{defaultTaskRPCEndpoint}
+	}
+	zclient, err := zrpc.NewClient(zrpc.RpcClientConf{
+		Endpoints: endpoints,
+		Target:    target,
+		NonBlock:  true,
+		Timeout:   int64(timeout / time.Millisecond),
+	})
+	if err != nil {
+		return nil, err
+	}
+	adapter := &TaskRPCAdapter{rpc: taskpb.NewTaskClient(zclient.Conn())}
+	if err := adapter.ping(timeout); err != nil {
+		return nil, err
+	}
+	return adapter, nil
+}
+
+func (a *TaskRPCAdapter) GetTaskForActiveSchedule(ctx context.Context, req activeports.TaskRequest) (activeports.TaskFact, bool, error) {
+	if err := a.ensureReady(); err != nil {
+		return activeports.TaskFact{}, false, err
+	}
+	payload, err := json.Marshal(taskcontracts.TaskFactRequest{
+		UserID: req.UserID,
+		TaskID: req.TaskID,
+		Now:    req.Now,
+	})
+	if err != nil {
+		return activeports.TaskFact{}, false, err
+	}
+	resp, err := a.rpc.GetTaskForActiveSchedule(ctx, &taskpb.JSONRequest{PayloadJson: payload})
+	if err != nil {
+		return activeports.TaskFact{}, false, taskRPCError(err)
+	}
+	var contractResp taskcontracts.TaskFactResponse
+	if err := json.Unmarshal(taskJSONBytes(resp), &contractResp); err != nil {
+		return activeports.TaskFact{}, false, err
+	}
+	return taskFactToActive(contractResp.Task), contractResp.Found, nil
+}
+
+func (a *TaskRPCAdapter) ensureReady() error {
+	if a == nil || a.rpc == nil {
+		return errors.New("task rpc adapter 未初始化")
+	}
+	return nil
+}
+
+func (a *TaskRPCAdapter) ping(timeout time.Duration) error {
+	if err := a.ensureReady(); err != nil {
+		return err
+	}
+	ctx, cancel := context.WithTimeout(context.Background(), timeout)
+	defer cancel()
+	_, err := a.rpc.Ping(ctx, &taskpb.StatusResponse{})
+	return taskRPCError(err)
+}
+
+func taskRPCError(err error) error {
+	if err == nil {
+		return nil
+	}
+	st, ok := status.FromError(err)
+	if !ok {
+		return err
+	}
+	if st.Code() == codes.NotFound {
+		return nil
+	}
+	if st.Code() == codes.Internal || st.Code() == codes.Unavailable || st.Code() == codes.DeadlineExceeded {
+		return fmt.Errorf("调用 task zrpc 服务失败: %w", err)
+	}
+	return err
+}
+
+func taskFactToActive(task taskcontracts.TaskFact) activeports.TaskFact {
+	return activeports.TaskFact{
+		ID:                 task.ID,
+		UserID:             task.UserID,
+		Title:              task.Title,
+		Priority:           task.Priority,
+		IsCompleted:        task.IsCompleted,
+		DeadlineAt:         task.DeadlineAt,
+		UrgencyThresholdAt: task.UrgencyThresholdAt,
+		EstimatedSections:  task.EstimatedSections,
+	}
+}
+
+func taskJSONBytes(resp *taskpb.JSONResponse) []byte {
+	if resp == nil || len(resp.DataJson) == 0 {
+		return []byte("null")
+	}
+	return resp.DataJson
+}
+
+func normalizeTaskRPCEndpoints(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
+}