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-generative-ui-u6.md(PR#408) — 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-generative-ui-u6.md

@@ -1,6 +1,6 @@
 # feature/generative-ui-u6 任务卡
 
-任务主记录：modules/documents/docs/proposals/2026-10-10-generative-ui-plugin.md r2（U6 节）；发布 PR：https://git-home.u1680832.nyat.app:30319/weichen/Agent-System-Dev/pulls/408（任务卡与 PR 描述同源）；状态：发布评审中；owner：weichen
+任务主记录：PR #408 https://git-home.u1680832.nyat.app:30319/weichen/Agent-System-Dev/pulls/408（merge 3f32fdacbc）；发布 PR：https://git-home.u1680832.nyat.app:30319/weichen/Agent-System-Dev/pulls/408（任务卡与 PR 描述同源）；状态：已完成（回填）；owner：weichen
 
 ## 基线与授权
 
@@ -64,7 +64,7 @@
 | 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：
 - 验证：<结论摘要 PASS/FAIL/SKIP/NOT_RUN 逐项；逐条证据由 make evidence 写入上方证据表>
@@ -199,3 +199,9 @@
   "receipt_sha256": "00850454f5b6cb27aab2b36f30aff9d919aba788a6eb4e7c6f213a3883c3e8d8"
 }
 ```
+
+## 闭合记录（card-autoclose 回填）
+
+- 依据：merge 3f32fdacbc5af91bd9212b2ded69f6559d1d92b2（PR #408）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 'Land Generative UI U6: workspace task pages and project aggregation (backend #163, frontend #62)' (#408) from feature/generative-ui-u6 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。