diff --git a/.doc/ops/CURRENT.md b/.doc/ops/CURRENT.md
index fd890979..e7b07976 100644
--- a/.doc/ops/CURRENT.md
+++ b/.doc/ops/CURRENT.md
@@ -5,7 +5,7 @@
 
 ## 焦点
 
-1. **DOC-RELIABILITY**: [M3 U8 已签，继续 U9](../test-reports/2026-09-15-taskrun-runmanifest-u8-test-report.md)（任务已归档 [2026-09-15-taskrun-runmanifest-u8](../archive/ops/2026-09-15-taskrun-runmanifest-u8.md)；U8 最后一句 **继续 U9**；**未签字前禁止 U10–U12**）
+1. **DOC-RELIABILITY**: [M3 U9 进行中](./short-term/2026-09-15-dataset-lifecycle-u9.md)（U8 已签 [继续 U9](../test-reports/2026-09-15-taskrun-runmanifest-u8-test-report.md)；本轮 mutex=`dataset`；**未签字前禁止 U10–U12**）
 2. **CHAT-INTENT**: [对话意图运行时状态](../audit/2026-09-13-conversation-intent-runtime-state.md)（`fix/conversation-intent-state`；与文档账本运行时无关）
 3. **CHAT**: [对话历史刷新](../audit/2026-09-13-chat-history-refresh-disappears.md)（认领仍 `in_progress`；gap 行已 PASS，以代码/handoff 为准收敛）
 
@@ -13,6 +13,7 @@
 
 | owner | task | branch | worktree | mutex | status |
 |-------|------|--------|----------|-------|--------|
+| Cursor | dataset-lifecycle-u9 | feature/dataset-lifecycle-u9 | - | dataset | in_progress |
 | Cursor | taskrun-runmanifest-u8 | feature/taskrun-runmanifest | - | taskrun | done |
 | Cursor | document-reliability-m1-live-and-m2 | refactor/document-reliability-pilot | .worktrees/refactor-document-reliability-pilot | workspace | done |
 | Codex | module-decoupling-remediation-plan | feature/module-decoupling-remediation | .worktrees/feature/module-decoupling-remediation | architecture-docs | done |
@@ -55,7 +56,7 @@
 > 新任务开始前登记。`branch` 必须为 `feature/<slug>` 或 `fix/<slug>`，**禁止** `dev` / `test` / `main`。同一 `mutex` 同时仅一个 `in_progress`。
 
 > workflow-plan 409 与治理鉴权 G1–G5 已收口（见 [test-report](../test-reports/2026-09-14-governance-action-level-authz-test-report.md)）。禁止终止或改写项目 143。
-> `document-reliability-pilot` U8 已签（继续 U9）。禁止 worktree 内 `env-service`。项目 143 只读，禁止终止。未签字前禁止 U10–U12。
+> `document-reliability-pilot` U9 进行中（U8 已签继续 U9）。禁止 worktree 内 `env-service`。项目 143 只读，禁止终止。未签字前禁止 U10–U12。
 
 ## 集成槽位
 
diff --git a/.doc/ops/short-term/2026-09-15-dataset-lifecycle-u9.md b/.doc/ops/short-term/2026-09-15-dataset-lifecycle-u9.md
new file mode 100644
index 00000000..320e36bd
--- /dev/null
+++ b/.doc/ops/short-term/2026-09-15-dataset-lifecycle-u9.md
@@ -0,0 +1,59 @@
+---
+title: "M3 U9 存量回填、migration corpus 与数据生命周期"
+status: in_progress
+created: 2026-09-15
+updated: 2026-09-15
+owner: Cursor
+branch: feature/dataset-lifecycle-u9
+worktree: "-"
+mutex: dataset
+---
+
+# M3 U9 存量回填、migration corpus 与数据生命周期
+
+## 目标
+
+只保留可解释的演示/回归数据，并持续验证旧数据迁移、重载和受控恢复。backfill 可暂停续跑，异常进 quarantine；八条轨道可重复；销毁默认 fail closed。
+
+## 范围
+
+- dataset registry（pinned / demo / regression / migration_baseline / ephemeral / quarantine）
+- checkpoint 分批 backfill：只枚举 snapshot、approved/commit event、completed chat turn
+- SKIP LOCKED 多 worker；禁止扫描 workspace
+- 销毁门禁：FAV coverage + 完整备份 restore + corpus + 精确 manifest + 双人批准 + quarantine 观察窗
+- restore 拒绝共享 env DSN；只允许 scratch
+- 八轨：clean / oldest-supported / previous / hazard / import / reload / rollback / artifact recovery
+
+## 非目标
+
+- U10–U12；不碰 `chat` / `intent` mutex
+- 不整支 merge `feature/final-artifact-vault`；不启用 `FAV_DEGRADED_READ`
+- 不修改历史 Goose；不销毁 `agent_system_dev/test/main`
+- 不终止或改写项目 143；worktree 内禁止 `env-service`
+
+## 步骤
+
+1. [ ] CURRENT 认领 `mutex=dataset`；从 `dev` 开 `feature/dataset-lifecycle-u9`
+2. [ ] Goose 00038 + `module-boundaries.yaml`
+3. [ ] `internal/artifactvault/backfill.go` + `internal/dataset` + `cmd/dataset`
+4. [ ] 硬化 `scripts/restore-system-db-drill.sh`
+5. [ ] 隔离库 + 八轨 + 目标包 `-race` + 占槽 rebuild
+6. [ ] 验收报告；最后一句只能是「继续 U10」或「停止扩面」
+
+## 验收标准
+
+- [ ] backfill 中断、重复、并发新终态时分母/分子可复算且不重复 artifact
+- [ ] legacy-v0 / 旧 schema / 高 ID / projection fork / 缺 snapshot → quarantine 或升级
+- [ ] restore 拒绝共享 DSN、错误 storage identity、篡改 manifest、缺权限
+- [ ] coverage / backup / corpus 任一失败阻止 destroy
+- [ ] 批准 dataset 导入后关系、SHA、sequence 可复算
+
+## 相关链接
+
+- Checklist: `.doc/ops/checklists/2026-09-14-module-decoupling-refactor-acceptance.md`
+- Plan: `.doc/remediation/2026-09-14-module-decoupling-refactor-plan.md` U9
+- Gate: `.doc/test-reports/2026-09-15-taskrun-runmanifest-u8-test-report.md`（继续 U9）
+
+## 证据 / 备注
+
+Goose 下一号开工前确认为 00038。