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/internal/feishu/mock.go

@@ -0,0 +1,139 @@
+package feishu
+
+import (
+	"context"
+	"fmt"
+	"sync"
+	"time"
+)
+
+// MockMode 描述 mock provider 下一次返回哪类结果。
+type MockMode string
+
+const (
+	MockModeSuccess       MockMode = "success"
+	MockModeTemporaryFail MockMode = "temporary_fail"
+	MockModePermanentFail MockMode = "permanent_fail"
+)
+
+// MockProvider 是进程内 mock provider。
+//
+// 职责边界：
+// 1. 只用于本地联调、单元测试和阶段性验收；
+// 2. 不做真实 HTTP 调用，直接根据预设 mode 返回 success / temporary_fail / permanent_fail；
+// 3. 保留调用历史，方便测试断言“有没有重复发飞书”。
+type MockProvider struct {
+	mu          sync.Mutex
+	defaultMode MockMode
+	queuedModes []MockMode
+	calls       []SendRequest
+}
+
+func NewMockProvider(defaultMode MockMode) *MockProvider {
+	if defaultMode == "" {
+		defaultMode = MockModeSuccess
+	}
+	return &MockProvider{defaultMode: defaultMode}
+}
+
+func (p *MockProvider) SetDefaultMode(mode MockMode) {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	if mode == "" {
+		mode = MockModeSuccess
+	}
+	p.defaultMode = mode
+}
+
+// PushModes 追加一组“一次性模式”。
+//
+// 说明：
+// 1. 先进先出消费，便于测试“先失败再成功”的重试路径；
+// 2. 队列用尽后回退到 defaultMode；
+// 3. 空模式会被自动忽略，避免测试代码误塞脏数据。
+func (p *MockProvider) PushModes(modes ...MockMode) {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	for _, mode := range modes {
+		if mode == "" {
+			continue
+		}
+		p.queuedModes = append(p.queuedModes, mode)
+	}
+}
+
+func (p *MockProvider) Calls() []SendRequest {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	copied := make([]SendRequest, len(p.calls))
+	copy(copied, p.calls)
+	return copied
+}
+
+// Send 按预设模式返回模拟结果。
+//
+// 步骤说明：
+// 1. 先记录本次请求，方便测试校验是否发生重复投递；
+// 2. 再按 queuedModes -> defaultMode 的顺序决定 outcome；
+// 3. 最后返回可落库审计的 request/response 摘要。
+func (p *MockProvider) Send(_ context.Context, req SendRequest) (SendResult, error) {
+	p.mu.Lock()
+	p.calls = append(p.calls, req)
+
+	mode := p.defaultMode
+	if len(p.queuedModes) > 0 {
+		mode = p.queuedModes[0]
+		p.queuedModes = p.queuedModes[1:]
+	}
+	p.mu.Unlock()
+
+	switch mode {
+	case MockModeTemporaryFail:
+		return SendResult{
+			Outcome:      SendOutcomeTemporaryFail,
+			ErrorCode:    ErrorCodeProviderTimeout,
+			ErrorMessage: "mock feishu provider temporary failure",
+			RequestPayload: map[string]any{
+				"notification_id": req.NotificationID,
+				"user_id":         req.UserID,
+				"preview_id":      req.PreviewID,
+				"target_url":      req.TargetURL,
+			},
+			ResponsePayload: map[string]any{
+				"mode":   string(mode),
+				"reason": "mock temporary failure",
+			},
+		}, nil
+	case MockModePermanentFail:
+		return SendResult{
+			Outcome:      SendOutcomePermanentFail,
+			ErrorCode:    ErrorCodePayloadInvalid,
+			ErrorMessage: "mock feishu provider permanent failure",
+			RequestPayload: map[string]any{
+				"notification_id": req.NotificationID,
+				"user_id":         req.UserID,
+				"preview_id":      req.PreviewID,
+				"target_url":      req.TargetURL,
+			},
+			ResponsePayload: map[string]any{
+				"mode":   string(mode),
+				"reason": "mock permanent failure",
+			},
+		}, nil
+	default:
+		return SendResult{
+			Outcome:           SendOutcomeSuccess,
+			ProviderMessageID: fmt.Sprintf("mock_feishu_%d", time.Now().UnixNano()),
+			RequestPayload: map[string]any{
+				"notification_id": req.NotificationID,
+				"user_id":         req.UserID,
+				"preview_id":      req.PreviewID,
+				"target_url":      req.TargetURL,
+			},
+			ResponsePayload: map[string]any{
+				"mode":   string(MockModeSuccess),
+				"status": "ok",
+			},
+		}, nil
+	}
+}