Version: 0.9.23.dev.260416

后端：
1. Memory 管理面 API 落地（“我的记忆”增删改查 + 恢复）
   - 补齐 List/Get/Create/Update/Delete/Restore 的 handler、请求模型与返回视图
   - 注册 `/api/v1/memory/items*` 路由并接入 MemoryHandler
   - 新增 memory item not found / invalid memory type / invalid memory content 三类管理面错误码
2. Memory Module / Service / Repo 扩展为“可管理 + 可治理”门面
   - 新增 NewModuleWithObserve / ObserveDeps，导出 GetItem / CreateItem / UpdateItem / DeleteItem / RestoreItem / RunDedupCleanup / MemoryObserver / MemoryMetrics
   - 新增手动新增、修改、恢复能力；删除链路切到 SoftDeleteByID；所有管理动作统一事务内写 audit，并桥接向量同步与管理面观测
   - 补齐 CreateItemFields / UpdateItemFields、单条 Create、管理侧字段更新、软删/恢复，以及 dedup 扫描/归档所需 repo 能力
   - 审计操作补齐 archive / restore
3. Memory 读侧与注入侧观测补齐
   - HybridRetrieve 返回 telemetry，统一记录 pinned hit / semantic hit / dedup drop / degraded / RAG fallback，并上报读取命中、去重丢弃、RAG 降级指标
   - AgentService 持有 memory observer / metrics；injectMemoryContext 对读取失败、空注入、成功注入补齐结构化日志与注入计数
4. Worker / 决策 / 向量同步链路治理增强
   - 召回结果显式携带 fallbackMode；hash 精确命中、rag→mysql 降级、最终动作统一写入决策观测
   - 接入 vectorSyncer / observer / metrics；为 job 重试、任务成功/失败、决策分布与 fallback 补齐打点；向量 upsert/delete 统一改走公共 Syncer，并收敛 parseMemoryID 解析逻辑
5. 启动层接入 Memory 观测依赖
   - 启动时创建 LoggerObserver + MetricsRegistry，并通过 NewModuleWithObserve 注入 memory 模块
前端：无
仓库：无

backend/memory/service/retrieve_merge.go

@@ -23,41 +23,50 @@ func (s *ReadService) HybridRetrieve(
 	effectiveSetting model.MemoryUserSetting,
 	limit int,
 	now time.Time,
-) ([]memorymodel.ItemDTO, error) {
+) ([]memorymodel.ItemDTO, retrieveTelemetry, error) {
+	telemetry := retrieveTelemetry{}
 	if s == nil || s.itemRepo == nil {
-		return nil, nil
+		return nil, telemetry, nil
 	}
 	if !effectiveSetting.MemoryEnabled {
-		return nil, nil
+		return nil, telemetry, nil
 	}
 
 	pinnedItems, err := s.retrievePinnedCandidates(ctx, req, effectiveSetting, now)
 	if err != nil {
-		return nil, err
+		return nil, telemetry, err
 	}
-	semanticItems, err := s.retrieveSemanticCandidates(ctx, req, effectiveSetting, limit, now)
+	telemetry.PinnedHitCount = len(pinnedItems)
+
+	semanticItems, semanticTelemetry, err := s.retrieveSemanticCandidates(ctx, req, effectiveSetting, limit, now)
 	if err != nil {
-		return nil, err
+		return nil, telemetry, err
 	}
+	telemetry.SemanticHitCount = len(semanticItems)
+	telemetry.Degraded = semanticTelemetry.Degraded
+	telemetry.RAGFallbackUsed = semanticTelemetry.RAGFallbackUsed
 
 	merged := make([]memorymodel.ItemDTO, 0, len(pinnedItems)+len(semanticItems))
 	merged = append(merged, pinnedItems...)
 	merged = append(merged, semanticItems...)
 	if len(merged) == 0 {
-		return nil, nil
+		return nil, telemetry, nil
 	}
 
+	beforeDedupCount := len(merged)
 	merged = dedupByID(merged)
 	merged = dedupByHash(merged)
 	merged = dedupByText(merged)
+	telemetry.DedupDropCount = beforeDedupCount - len(merged)
 	merged = RankItems(merged, now)
 	merged = applyTypeBudget(merged, s.cfg)
 	if len(merged) == 0 {
-		return nil, nil
+		return nil, telemetry, nil
 	}
+	telemetry.FinalCount = len(merged)
 
 	_ = s.itemRepo.TouchLastAccessAt(ctx, collectItemDTOIDs(merged), now)
-	return merged, nil
+	return merged, telemetry, nil
 }
 
 func (s *ReadService) retrievePinnedCandidates(
@@ -81,20 +90,26 @@ func (s *ReadService) retrieveSemanticCandidates(
 	effectiveSetting model.MemoryUserSetting,
 	limit int,
 	now time.Time,
-) ([]memorymodel.ItemDTO, error) {
+) ([]memorymodel.ItemDTO, semanticRetrieveTelemetry, error) {
+	telemetry := semanticRetrieveTelemetry{}
 	queryText := strings.TrimSpace(req.Query)
 	if queryText == "" {
-		return nil, nil
+		return nil, telemetry, nil
 	}
 
 	candidateLimit := hybridSemanticTopK(s.cfg, limit)
 	if s.cfg.RAGEnabled && s.ragRuntime != nil {
 		items, err := s.retrieveSemanticCandidatesByRAG(ctx, req, effectiveSetting, candidateLimit, now)
 		if shouldReturnSemanticRAGResult(items, err) {
-			return items, nil
+			telemetry.HitCount = len(items)
+			return items, telemetry, nil
 		}
+		telemetry.Degraded = true
+		telemetry.RAGFallbackUsed = true
 	}
-	return s.retrieveSemanticCandidatesByMySQL(ctx, req, effectiveSetting, candidateLimit, now)
+	items, err := s.retrieveSemanticCandidatesByMySQL(ctx, req, effectiveSetting, candidateLimit, now)
+	telemetry.HitCount = len(items)
+	return items, telemetry, err
 }
 
 func (s *ReadService) retrieveSemanticCandidatesByRAG(