Close 1 merged task card(s) and archive them

Why: branches merged into main had left their task cards open; backfill status and archive to prevent bookkeeping debt.
Evidence: feature-ext-11-scoped-host-factory.md(PR#271) — merges verified via git log --merges against origin/main.
Impact: .task/*.md moved to .task/archive/ with status backfilled; no code or submodule change.
Refs: task.sh close (card-autoclose-r1)

.task/archive/feature-ext-11-scoped-host-factory.md

@@ -1,6 +1,6 @@
 # feature/ext-11-scoped-host-factory 任务卡
 
-任务主记录：<PR 链接，交付前填写>；状态：进行中；owner：weichen
+任务主记录：PR #271 https://git-home.u1680832.nyat.app:30319/weichen/Agent-System-Dev/pulls/271（merge 92295ff211）；状态：已完成（回填）；owner：weichen
 
 ## 基线与授权
 
@@ -80,7 +80,7 @@ owner、KnowledgeDelete 前缀强制仍拒 manual（同构性）。
 | 时间(UTC) | 命令 | 被测HEAD | exit | 来源 | sha256(16) |
 |---|---|---|---|---|---|
 
-## 结果与验证（完成后填写）
+## 结果与验证
 
 - 结果：完成。Backend PR #108（EXT-11 公开面+组合根接线，SurfaceVersion
   2.4.0-experimental）；Dev gitlink bump PR。
@@ -332,3 +332,9 @@ owner、KnowledgeDelete 前缀强制仍拒 manual（同构性）。
   "receipt_sha256": "c1079697f3ca0653ff4584ec7e3a9f3ba8b8d582ef6f1dbd0658d42f7055a749"
 }
 ```
+
+## 闭合记录（card-autoclose 回填）
+
+- 依据：merge 92295ff211ae6153e0725d868b1774e0cdfebfc6（PR #271）已包含于 origin/main，分支成果已落盘；本段为合入后回填。
+- 合并主题：Merge pull request 'Bump backend to the EXT-11 scoped-host factory (Backend #108)' (#271) from feature/ext-11-scoped-host-factory into main
+- 归档：随闭合移入 .task/archive/；任务执行期的过程证据见原任务记录与 PR。