归档10-05错误码可解释性与付款就绪任务（09-05-error-explainability-payment-readiness）

591条历史豁免基线已清零，794条新增reasonCode已通过候选分支合并落地至
origin/main（46a70aa5），主链路零例外，无剩余阻塞验收项。
work landed via 已删除的候选分支而非专属分支，故用
--skip-branch-validation 归档。

.trellis/tasks/archive/2026-09/09-05-error-explainability-payment-readiness/task.json

@@ -3,7 +3,7 @@
   "name": "error-explainability-payment-readiness",
   "title": "错误可解释性与付款就绪治理",
   "description": "建立稳定业务错误原因码与渐进 parity 门禁，并以付款批次实时 readiness 消除点击后才暴露的资料阻断。",
-  "status": "in_progress",
+  "status": "completed",
   "dev_type": null,
   "scope": null,
   "package": null,
@@ -11,7 +11,7 @@
   "creator": "shunli",
   "assignee": "shunli",
   "createdAt": "2026-09-05",
-  "completedAt": null,
+  "completedAt": "2026-09-26",
   "branch": null,
   "base_branch": "main",
   "worktree_path": null,