Version: 0.9.68.dev.260504

后端：
1. 阶段 3 notification 服务边界落地，新增 `cmd/notification`、`services/notification`、`gateway/notification`、`shared/contracts/notification` 和 notification port，按 userauth 同款最小手搓 zrpc 样板收口
2. notification outbox consumer、relay 和 retry loop 迁入独立服务入口，处理 `notification.feishu.requested`，gateway 改为通过 zrpc client 调用 notification
3. 清退旧单体 notification DAO/model/service/provider/runner 和 `service/events/notification_feishu.go`，旧实现不再作为活跃编译路径
4. 修复 outbox 路由归属、dispatch 启动扫描、Kafka topic 探测/投递超时、sending 租约恢复、毒消息 MarkDead 错误回传和 RPC timeout 边界
5. 同步调整 active-scheduler 触发通知事件、核心 outbox handler、MySQL 迁移边界和 notification 配置

文档：
1. 更新微服务迁移计划，将阶段 3 notification 标记为已完成，并明确下一阶段从 active-scheduler 开始

backend/services/notification/dao/channel.go

@@ -0,0 +1,127 @@
+package dao
+
+import (
+	"context"
+	"errors"
+	"time"
+
+	notificationmodel "github.com/LoveLosita/smartflow/backend/services/notification/model"
+	"gorm.io/gorm"
+	"gorm.io/gorm/clause"
+)
+
+// ChannelDAO 管理用户外部通知通道配置。
+//
+// 职责边界：
+// 1. 只负责 user_notification_channels 的基础读写；
+// 2. 不负责 webhook 请求发送、notification_records 状态机或 outbox 消费；
+// 3. webhook_url / bearer_token 的脱敏由 service 层处理，DAO 保持真实持久化值。
+type ChannelDAO struct {
+	db *gorm.DB
+}
+
+func NewChannelDAO(db *gorm.DB) *ChannelDAO {
+	return &ChannelDAO{db: db}
+}
+
+func (d *ChannelDAO) WithTx(tx *gorm.DB) *ChannelDAO {
+	return &ChannelDAO{db: tx}
+}
+
+func (d *ChannelDAO) ensureDB() error {
+	if d == nil || d.db == nil {
+		return errors.New("notification channel dao 未初始化")
+	}
+	return nil
+}
+
+// UpsertUserNotificationChannel 按 user_id + channel 幂等保存用户通知配置。
+//
+// 说明：
+// 1. 只覆盖开关、webhook、鉴权配置和 updated_at；
+// 2. 不清空 last_test_*，避免用户保存配置后丢掉最近一次测试结果；
+// 3. channel.ID 由数据库自增，调用方不应依赖传入 ID。
+func (d *ChannelDAO) UpsertUserNotificationChannel(ctx context.Context, channel *notificationmodel.UserNotificationChannel) error {
+	if err := d.ensureDB(); err != nil {
+		return err
+	}
+	if channel == nil || channel.UserID <= 0 || channel.Channel == "" {
+		return errors.New("notification channel 必须包含 user_id 和 channel")
+	}
+	now := time.Now()
+	values := map[string]any{
+		"user_id":      channel.UserID,
+		"channel":      channel.Channel,
+		"enabled":      channel.Enabled,
+		"webhook_url":  channel.WebhookURL,
+		"auth_type":    channel.AuthType,
+		"bearer_token": channel.BearerToken,
+		"created_at":   now,
+		"updated_at":   now,
+	}
+	return d.db.WithContext(ctx).
+		Model(&notificationmodel.UserNotificationChannel{}).
+		Clauses(clause.OnConflict{
+			Columns: []clause.Column{{Name: "user_id"}, {Name: "channel"}},
+			DoUpdates: clause.Assignments(map[string]any{
+				"enabled":      channel.Enabled,
+				"webhook_url":  channel.WebhookURL,
+				"auth_type":    channel.AuthType,
+				"bearer_token": channel.BearerToken,
+				"updated_at":   now,
+			}),
+		}).
+		Create(values).Error
+}
+
+// GetUserNotificationChannel 查询用户指定通知通道配置。
+func (d *ChannelDAO) GetUserNotificationChannel(ctx context.Context, userID int, channel string) (*notificationmodel.UserNotificationChannel, error) {
+	if err := d.ensureDB(); err != nil {
+		return nil, err
+	}
+	if userID <= 0 || channel == "" {
+		return nil, gorm.ErrRecordNotFound
+	}
+	var row notificationmodel.UserNotificationChannel
+	err := d.db.WithContext(ctx).
+		Where("user_id = ? AND channel = ?", userID, channel).
+		First(&row).Error
+	if err != nil {
+		return nil, err
+	}
+	return &row, nil
+}
+
+// DeleteUserNotificationChannel 删除用户指定通知通道配置。
+//
+// 说明：当前表不保留软删除列；删除后再次保存会重新创建配置。
+func (d *ChannelDAO) DeleteUserNotificationChannel(ctx context.Context, userID int, channel string) error {
+	if err := d.ensureDB(); err != nil {
+		return err
+	}
+	if userID <= 0 || channel == "" {
+		return nil
+	}
+	return d.db.WithContext(ctx).
+		Where("user_id = ? AND channel = ?", userID, channel).
+		Delete(&notificationmodel.UserNotificationChannel{}).Error
+}
+
+// UpdateUserNotificationChannelTestResult 回写用户 webhook 测试结果。
+func (d *ChannelDAO) UpdateUserNotificationChannelTestResult(ctx context.Context, userID int, channel string, status string, testErr string, testedAt time.Time) error {
+	if err := d.ensureDB(); err != nil {
+		return err
+	}
+	if userID <= 0 || channel == "" {
+		return errors.New("user_id 和 channel 不能为空")
+	}
+	updates := map[string]any{
+		"last_test_status": status,
+		"last_test_error":  testErr,
+		"last_test_at":     &testedAt,
+	}
+	return d.db.WithContext(ctx).
+		Model(&notificationmodel.UserNotificationChannel{}).
+		Where("user_id = ? AND channel = ?", userID, channel).
+		Updates(updates).Error
+}