Version: 0.9.76.dev.260505

后端：
1.阶段 6 agent / memory 服务化收口
- 新增 cmd/agent 独立进程入口，承载 agent zrpc server、agent outbox relay / consumer 和运行时依赖初始化
- 补齐 services/agent/rpc 的 Chat stream 与 conversation meta/list/timeline、schedule-preview、context-stats、schedule-state unary RPC
- 新增 gateway/client/agent 与 shared/contracts/agent，将 /api/v1/agent chat 和非 chat 门面切到 agent zrpc
- 收缩 gateway 本地 AgentService 装配，双 RPC 开关开启时不再初始化本地 agent 编排、LLM、RAG 和 memory reader fallback
- 将 backend/memory 物理迁入 services/memory，私有实现收入 internal，保留 module/model/observe 作为 memory 服务门面
- 调整 memory outbox、memory reader 和 agent 记忆渲染链路的 import 与服务边界，cmd/memory 独占 memory worker / consumer
- 关闭 gateway 侧 agent outbox worker 所有权，agent relay / consumer 由 cmd/agent 独占，gateway 仅保留 HTTP/SSE 门面与迁移期开关回退
- 更新阶段 6 文档，记录 agent / memory 当前切流点、smoke 结果，以及 backend/client 与 gateway/shared 的目录收口口径

backend/services/memory/internal/cleanup/dedup_policy.go

@@ -0,0 +1,73 @@
+package cleanup
+
+import (
+	"sort"
+	"time"
+
+	"github.com/LoveLosita/smartflow/backend/model"
+)
+
+const dedupRecentTieWindow = 24 * time.Hour
+
+// DedupDecision 描述单个重复组的治理结论。
+type DedupDecision struct {
+	Keep    model.MemoryItem
+	Archive []model.MemoryItem
+}
+
+// DecideDedupGroup 决定一组重复 active 记忆中“保留谁、归档谁”。
+//
+// 步骤化说明：
+// 1. 先按“最近更新时间”判断谁更值得保留，符合治理计划里的“优先保留最近更新”；
+// 2. 若更新时间非常接近，再比较 confidence/importance，避免刚好相差几秒就误保留低质量版本；
+// 3. 最后用主键逆序兜底，保证同组治理结果稳定可复现。
+func DecideDedupGroup(items []model.MemoryItem) DedupDecision {
+	if len(items) == 0 {
+		return DedupDecision{}
+	}
+
+	ordered := make([]model.MemoryItem, len(items))
+	copy(ordered, items)
+	sort.SliceStable(ordered, func(i, j int) bool {
+		return preferDedupKeep(ordered[i], ordered[j])
+	})
+
+	return DedupDecision{
+		Keep:    ordered[0],
+		Archive: ordered[1:],
+	}
+}
+
+func preferDedupKeep(left model.MemoryItem, right model.MemoryItem) bool {
+	leftTime := dedupBaseTime(left)
+	rightTime := dedupBaseTime(right)
+
+	diff := leftTime.Sub(rightTime)
+	if diff < 0 {
+		diff = -diff
+	}
+	if diff > dedupRecentTieWindow {
+		return leftTime.After(rightTime)
+	}
+
+	if left.Confidence != right.Confidence {
+		return left.Confidence > right.Confidence
+	}
+	if left.Importance != right.Importance {
+		return left.Importance > right.Importance
+	}
+	if !leftTime.Equal(rightTime) {
+		return leftTime.After(rightTime)
+	}
+	return left.ID > right.ID
+}
+
+func dedupBaseTime(item model.MemoryItem) time.Time {
+	if item.UpdatedAt != nil {
+		return *item.UpdatedAt
+	}
+	if item.CreatedAt != nil {
+		return *item.CreatedAt
+	}
+	return time.Time{}
+}