docs: order the issue #18 work so nothing deletes the shared table

The plan's one irreversible risk is the worst-case test itself. It
deliberately lets the script fall through to the shared table, and the
account in .env is a superuser, so running it before the sandbox role
exists would delete every expired row in there. All eleven rows on that
table predate any cutoff the tests use.

That forces the order: factory, then the retention tests move onto an
owner role, and only then does the case get written. Review caught that
the original order also made the --table integration cases impossible
to fail first, since the tool would already be implemented by the time
they were written. Same fix resolves both.

The worst-case case has no red-first path at all. Turning it red means
running it as the superuser, which is the thing being prevented, so its
evidence is the probe in the finding instead, and the plan says so
rather than calling it verified.

One acceptance criterion in the design turned out to be unrunnable: the
hint line only prints on the Postgres branch, so no unit test that
never connects can assert it. Corrected in place.

research-wiki/index.md

@@ -1,8 +1,8 @@
 # Research Wiki 索引
 
-> 自动生成，更新时间：2026-08-26 04:49 UTC
+> 自动生成，更新时间：2026-08-26 11:28 UTC
 
-## design (38)
+## design (39)
 - [2026-07-20-m1-core-design](designs/2026-07-20-m1-core-design.md) `design:2026-07-20-m1-core-design`
 - [2026-07-20-m2-distributed-design](designs/2026-07-20-m2-distributed-design.md) `design:2026-07-20-m2-distributed-design`
 - [2026-07-21-m25-resilience-design](designs/2026-07-21-m25-resilience-design.md) `design:2026-07-21-m25-resilience-design`
@@ -28,6 +28,7 @@
 - [issue #12: 遥测表的正文体量、保留期与访问控制](designs/issue12-telemetry-retention.md) `design:issue12-telemetry-retention`
 - [issue #13: 遥测 schema 自动 ALTER 降级为按后端不对称的显式档位](designs/issue13-schema-mode.md) `design:issue13-schema-mode`
 - [issue #15: 遥测连接池的资源语义与生命周期](designs/issue15-telemetry-pool-lifecycle.md) `design:issue15-telemetry-pool-lifecycle`
+- [issue #18: 隔离靠权限强制,目标靠显式声明](designs/2026-08-26-issue18-pg-test-isolation-design.md) `design:2026-08-26-issue18-pg-test-isolation`
 - [M1 核心里程碑设计:公共签名冻结与治理栈落地](designs/m1-core-design.md) `design:m1-core-design`
 - [M2 分布式:Redis 治理后端+背压+Postgres 遥测+pricing+Embedding+压测 harness](designs/m2-distributed.md) `design:m2-distributed`
 - [M2.5 治理韧性: 半死源隔离与健康感知调度](designs/m25-resilience.md) `design:m25-resilience`
@@ -42,13 +43,14 @@
 - [调用方自定义维度设计(issue #11)](designs/issue11-caller-dimensions.md) `design:issue11-caller-dimensions`
 - [采样参数透传设计(issue #4)](designs/sampling-params.md) `design:sampling-params`
 
-## finding (13)
+## finding (14)
 - [2026-07-20-m2-soak-workload](findings/2026-07-20-m2-soak-workload.md) `finding:2026-07-20-m2-soak-workload`
 - [2026-07-21-m25-acceptance](findings/2026-07-21-m25-acceptance.md) `finding:2026-07-21-m25-acceptance`
 - [2026-07-21-p6-soak-baseline](findings/2026-07-21-p6-soak-baseline.md) `finding:2026-07-21-p6-soak-baseline`
 - [2026-07-22-m4-acceptance](findings/2026-07-22-m4-acceptance.md) `finding:2026-07-22-m4-acceptance`
 - [2026-07-22-p7-ocr-soak](findings/2026-07-22-p7-ocr-soak.md) `finding:2026-07-22-p7-ocr-soak`
 - [issue #16/#17 实测: M3 推理正常,失效的是推理的可观测信号](findings/2026-08-25-thinking-observability-regression.md) `finding:2026-08-25-thinking-observability-regression`
+- [issue #18 实测: 偶发红的是安全网本身,不是被测脚本](findings/2026-08-26-issue18-shared-pg-test-isolation.md) `finding:2026-08-26-issue18-shared-pg-test-isolation`
 - [M2 verifier 三项 Important 补齐(不变量接线/网关保护/P3 验收)](findings/m2-verifier-fixes.md) `finding:m2-verifier-fixes`
 - [M2 真实数据压测: 场景矩阵与数据清单](findings/m2-soak-workload.md) `finding:m2-soak-workload`
 - [M2.5 验收: P6 同场景 58.1% → 98.96%](findings/m25-acceptance.md) `finding:m25-acceptance`
@@ -57,7 +59,7 @@
 - [P7 OCR soak 验收: 99.73% 与 13 不变量全 PASS](findings/p7-ocr-soak.md) `finding:p7-ocr-soak`
 - [推理开关与 reasoning_tokens: 供应商实测与业界做法](findings/2026-08-02-thinking-switch-and-reasoning-tokens.md) `finding:2026-08-02-thinking-switch-and-reasoning-tokens`
 
-## plan (33)
+## plan (34)
 - [2026-07-20-m1-core-plan](plans/2026-07-20-m1-core-plan.md) `plan:2026-07-20-m1-core-plan`
 - [2026-07-20-m2-distributed-plan](plans/2026-07-20-m2-distributed-plan.md) `plan:2026-07-20-m2-distributed-plan`
 - [2026-07-21-m25-resilience-plan](plans/2026-07-21-m25-resilience-plan.md) `plan:2026-07-21-m25-resilience-plan`
@@ -74,6 +76,7 @@
 - [2026-08-19-issue13-schema-mode](plans/2026-08-19-issue13-schema-mode.md) `plan:2026-08-19-issue13-schema-mode`
 - [2026-08-24-issue15-telemetry-pool-lifecycle](plans/2026-08-24-issue15-telemetry-pool-lifecycle.md) `plan:2026-08-24-issue15-telemetry-pool-lifecycle`
 - [est_tokens 解耦实施计划](plans/est-tokens-decoupling.md) `plan:est-tokens-decoupling`
+- [issue #18 实现计划: 权限边界替代行数快照 + --table 锁死目标](plans/2026-08-26-issue18-pg-test-isolation.md) `plan:2026-08-26-issue18-pg-test-isolation`
 - [issue #8 实施计划: stall 非生产性等待口径](plans/issue8-stall-budget-plan.md) `plan:issue8-stall-budget-plan`
 - [M1 核心里程碑实现计划](plans/m1-core-plan.md) `plan:m1-core-plan`
 - [M2 分布式实现计划](plans/m2-distributed.md) `plan:m2-distributed`