Record approved audit write-order guard and failing replay

Why: Explicit low audit IDs can bypass the old default function and disappear across fixed-cutoff pages.

Evidence: User approved the immutable r1 correction; the exact isolated PostgreSQL RED receipt is preserved byte-for-byte.

Impact: Authorizes only isolated all-writer guard and offline-copy testing; live migration remains outside scope.

Refs: feature/rdm-two-trees-latest-templates W9

docs/proposals/2026-10-14-rdm-two-trees-latest-templates.md

@@ -97,7 +97,7 @@ RDM保有领域、schema/事件与业务权限；Backend仅补必要通用公开
 - [W2/W4实施顺序修订r1](../records/2026-10-14-rdm-two-trees-latest-templates/rdm-two-trees-stage6-w2-w4-sequence-adjustment-r1.md)：W2的并发字典修订与事务回滚在当前RDM分支保留两条RED；将已批准W4事务隔离基础W4a移到W3之前，由W2 owner在同一工作区修复，W3仍等待DHF U1合入，W4提案/真人确认W4b仍在W3后。用户于本聊天call_c6f6ccef6a5b4e92ad473d85623d4b5f第0项选择“批准修订，先实现 W4a（推荐）”；批准对象SHA256 `aaf8c091772149a3547cbec272a7f38de3a47cc41c84b7bcef05e74510efbacf`，原稿保留评审前状态。
 - [W9 PostgreSQL审计截止水位修订r1](../records/2026-10-14-rdm-two-trees-latest-templates/rdm-two-trees-stage6-w9-pg-audit-cutoff-adjustment-r1.md)：现有序列ID可低号晚提交，固定页游标缺少已提交前缀保证；在序列CACHE 1等前提下串行化在线审计ID分配，并补迁移/回滚/离线复制检查。用户于本聊天call_22d8212219f946d8b117837d7e5ccb3f第0项选择“批准修订，实施并验证（推荐）”；批准对象SHA256 `2357b715a7c8f3451b34cc25a578d655e8a48f3f26d9cf7561ea7a13998ca857`，只放行隔离分支，真实运行库迁移仍按原边界。
 - [W6项目模型历史来源逐项复验修订r1](../records/2026-10-14-rdm-two-trees-latest-templates/rdm-two-trees-stage6-w6-source-recheck-design-adjustment-r1.md)：独立复审发现候选`resolve_goal`把完整user/judge正文写入长期回执，已有RED证实。以实际纳入的稳定来源ID/版本/hash经可选领域接口逐项重验，移除原文持久化；用户于本聊天call_751be0cc02914fe2b1fe591042d029ec第0项选择“批准修订，继续 W6（推荐）”。批准对象SHA256 `d46168392d4fd8ea9aa7f73206be039268aff6be100faef63efa052323511616`；仅放行隔离分支，真实库迁移/tag/阶段验收仍按原边界。
-- [W9全部审计写入口截止水位修订r1](../records/2026-10-14-rdm-two-trees-latest-templates/rdm-two-trees-stage6-w9-all-writers-cutoff-adjustment-r1.md)：独立复审发现并在隔离PG以测试-only RED实测显式在线低ID绕过已批r1默认函数，`committed-prefix`误报并跨页漏行。建议所有INSERT同事务锁/单调门禁、UPDATE/DELETE不可改、排他离线复制与只前进序列；影响数据库门禁、迁移和运行成本，待人工评审。当前W9 `63ebc85`不能强报已提交前缀。SHA256 `44f6f7cd34bf95a9c1eb844bfdd70a5c2233e1b5ffc89b3091359dcb5fc3b5d8`。
+- [W9全部审计写入口截止水位修订r1](../records/2026-10-14-rdm-two-trees-latest-templates/rdm-two-trees-stage6-w9-all-writers-cutoff-adjustment-r1.md)：独立复审发现并在隔离PG以测试-only RED实测显式在线低ID绕过已批r1默认函数，`committed-prefix`误报并跨页漏行。所有INSERT同事务锁/单调门禁、UPDATE/DELETE不可改、排他离线复制与只前进序列由用户于本聊天call_4f521a6ddd0542178769f8d7231916b5第0项选择“批准修订，隔离实施验证（推荐）”；批准对象SHA256 `44f6f7cd34bf95a9c1eb844bfdd70a5c2233e1b5ffc89b3091359dcb5fc3b5d8`。仅隔离分支续办，真实运行库迁移仍未放行；当前W9 `63ebc85`本身不能强报已提交前缀。
 
 ## 阶段6启动记录
 

docs/records/2026-10-14-rdm-two-trees-latest-templates/README.md

@@ -16,7 +16,8 @@
 - [W2/W4关键依赖顺序修订r1](rdm-two-trees-stage6-w2-w4-sequence-adjustment-r1.md)：用户已批准W4a先行，原对象保留评审前状态。
 - [W9 PostgreSQL审计截止水位修订r1](rdm-two-trees-stage6-w9-pg-audit-cutoff-adjustment-r1.md)：用户已批准隔离分支实现/验证；真实运行库迁移未获放行，原对象保留评审前状态。
 - [W6项目模型历史来源逐项复验修订r1](rdm-two-trees-stage6-w6-source-recheck-design-adjustment-r1.md)：长期回执原文RED后的X1受影响公开合同已获用户批准；原对象保留评审前状态，W6仅隔离分支续办。
-- [W9全部审计写入口截止水位修订r1](rdm-two-trees-stage6-w9-all-writers-cutoff-adjustment-r1.md)：显式在线ID绕过后的DB门禁与排他复制修订；待人工评审，强coverage暂不放行。
+- [W9全部审计写入口截止水位修订r1](rdm-two-trees-stage6-w9-all-writers-cutoff-adjustment-r1.md)：显式在线ID绕过后的DB门禁与排他复制修订已获用户批准，原对象保留评审前状态；强coverage仍待修复和验证。
+- [W9隔离PG显式低ID跨页RED原始SELF收据](evidence/backend-w9-explicit-low-red-20261014-01.json)：从Backend独立工作树源码外收据逐字节复制，副本与原件SHA256均为`21999df9ca7304288df42a5a0ac62687870636291bc61a8b1340fd92729bfd96`；退出码1是预期的失败用例，不是代码已修复或验收通过。
 - [阶段4源码与在途依赖快照](stage4-sources.json)
 - [模板与会议来源台账](rdm-two-trees-source-inventory.json)
 - [旧DOC源码补充](rdm-two-trees-legacy-source-addendum.md)