docs(audit): fifth-batch ledger — quota atomic gate closed (audit #4)

The deferred-seams entry that waited for a real-Postgres harness is struck:
ClaimServer owns the gate now, proven red-then-green by the pgint concurrency
test (two claims, one win, one 403), and the storage-cache zeroing found in the
same pass is recorded with its hermetic test. auditfix19 is live on the VM.

AUDIT-2026-09-22.md

@@ -24,6 +24,7 @@ IPv6-only 接入（`ssh -6 -i ~/.ssh/id_ed25519 root@fdb2:2c26:f4e4:0:21c:42ff:f
 | 20 | **验证邮箱唯一性只存在于注释里**：errors.go/repo.go 都声称迁移 0010 建了 `users_verified_email_unique` 部分唯一索引、`VerifyEmailOTP` 会返回 `ErrEmailTaken`；实际上**索引从未创建**、`ErrEmailTaken` 全仓库从未被返回 → 两个账号可同时验证一个邮箱，而登录门正是按 verified email 解析账号 → 同一邮箱的登录码归谁由数据库任意决定 | pgint 首跑即红：第二账号验证同邮箱返回 `nil`；`grep users_verified_email_unique internal/store/migrations/*.sql` 零命中。真机复验（auditfix17 邮箱 409 演练）：同码二次 verify 仍 409（码未被消费） | 新增迁移 `0020_verified_email_unique.sql`（`lower(email) WHERE email_verified`）；`VerifyEmailOTP` 在消费码**前**查「他人已验证」→ `ErrEmailTaken`（不消费码、不扣次数），并把并发唯一冲突映射为同一答案；handler 新增 409 `email_taken`。提交 `b6ef27c`；PG 契约测试基建 `2a55a0d`（`-tags pgint`，见 CONTRIBUTING） |
 | 21 | **admin 改邮箱不清 verified**：`UpdateUser` 写入新地址但保留 `email_verified=true` → 面板改错一个字符就能让登录码寄到别人邮箱（该 flag 正是邮箱登录解析/寄码的依据）；fake 同错 | pgint 契约测试 | 改地址时同写 `email_verified = email_verified AND email IS NOT DISTINCT FROM 新值`（同值 no-op 保留证明；换值即清除）；fake 同步。提交 `d1ec40f`。真机验证：PATCH→`f`、PATCH 回原值仍 `f`、玩家重验证→`t` |
 | 22 | **`role='owner'` 是死信**：迁移 0011 加了 owner 角色并把全部用户管理路由压在 `IsOwner()` 上，但**没有任何代码写过 `owner`**——breakGlass(`UpsertOwner`)、setup MC 绑定(`CompleteOwnerSetup`)、重置路径一律写 `admin` → 全新安装的整个 owner 层（用户列表/创建/编辑/禁用/删除/配额/会话）不可达；且新角色没进各处 staff 判定（op-login 只认 admin、玩家邮箱门只拒 admin、reclaim 保护与 AdminExists 只认 admin）；面板一旦有 owner 行还可被降级/删除/禁用 | 真机：owner 会话加载 `/api/v1/users` 403；promote 后 200。op-login：修复前 owner start 中立不发码，修复后铸请求+finish 得 `role=owner` 会话 | `UpsertOwner`/`CompleteOwnerSetup` 改写 `role='owner'`（冲突臂重断言，即 0011 文档的 promote 路径）；op-login 双端改 `staffRole`；玩家邮箱门改 `role != 'user'`；`IsProtectedAdminLink`/`AdminExists` 计入 owner；面板新增守卫：owner 行不可降级/删除/禁用（用户名/邮箱编辑仍可）。提交 `e0d2378` |
+| 23 | **配额门非原子 + storage 缓存被清零**：(a) audit #4：`QuotaCheck` 与 `ClaimServer` 两条语句，同一用户并发认领两台无主服可双双通过 `max_servers`（deferred-seams 曾把这条挂为“只能在真 PG 上关闭”）；(b) 更隐蔽：PATCH 资源时 `UpdateServerResources(..., 0)` 把本不能改的 storage 缓存写 0，而缓存列是配额聚合的**唯一**输入 → 此后该服的 storage 维度在配额里凭空消失 | (a) 新增 pgint 并发测试：修复前两台全赢；修复后恰 1 赢 + 1 `ErrQuotaExceeded`，DB 只 1 行 owned；(b) hermetic 测试 `TestPatchServerPreservesStorageCache`（修复前 `resourceUpdates` 里 storage=0） | (a) 门槛进 `ClaimServer`：同一事务内 `pg_advisory_xact_lock(hashtext(user_id))` + 四维重查（与 `QuotaCheck` 共用 `quotaAllows` 防漂移）+ 行 `FOR UPDATE`，两个 claim handler 把 `ErrQuotaExceeded` 映射为与串行一致的 403；(b) resize 前读取现值并透传 storage。提交 `bb68fef`；deferred-seams 对应条目核销 |
 
 ## 待决策台账（未修）
 
@@ -75,6 +76,7 @@ IPv6-only 接入（`ssh -6 -i ~/.ssh/id_ed25519 root@fdb2:2c26:f4e4:0:21c:42ff:f
 - **邮箱唯一性真机 409 演练（auditfix17）**：owner 已验地址被玩家 onboarding 流程二次验证 → 第一次 409 `email_taken`；**同码重放仍是 409**（证明码未被消费，符合契约；若被消费会是 400）。
 - **admin 改邮箱清 verified 真机演练（auditfix18）**：PATCH player.test → `[email protected]` 后 `email_verified=f`；PATCH 回原地址仍 `f`；玩家走 onboarding 重验证 → `t`。
 - **owner 角色真机闭环（auditfix18）**：owner 行按 0011 文档升级路径置 `role='owner'` → `GET /api/v1/users` 200（修复前 403）；owner op-login start 铸请求+发码、finish 得 `role=owner` 会话；PATCH owner role / DELETE owner / DISABLE owner 全部 403；玩家邮箱登录回归 200。
+- **配额原子门（第五批，`bb68fef`，auditfix19 已上线）**：pgint 并发实证（真实 PG 上两路并发认领：恰 1 赢 + 1 `ErrQuotaExceeded`；修复前两路全赢）；`docs/deferred-seams.md` 的 audit #4 条目核销。
 
 ## 结论：离"生产可用"还差什么（按优先级）
 

docs/deferred-seams.md

@@ -83,8 +83,11 @@ or a real upstream account to run it against — not an implementation.
 These are decisions, not backlog. Each names the condition under which it would be
 worth revisiting.
 
-- `internal/api/pgrepo.go:281` — the quota check and `ClaimServer` are two statements
+- ~~`internal/api/pgrepo.go:281` — the quota check and `ClaimServer` are two statements
-  (audit #4 TOCTOU). Closeable only against a real Postgres.
+  (audit #4 TOCTOU). Closeable only against a real Postgres.~~ **Closed** — the gate
+  moved inside `ClaimServer` (advisory lock + re-check + UPDATE in one transaction),
+  red-then-green in the pgint suite, which is exactly the real-Postgres harness this
+  line was waiting for.
 - `internal/api/api.go:671` — `cooldownLimiter` is process-local, so across N api
   replicas a caller could draw up to N OTP codes per window. The intra-replica burst
   is closed; cross-replica bounding needs a shared store, out of scope for a