Record the agent stack proposal verification

Why: The completion claim needs the precheck, sync, and combination test evidence on the task card.
Evidence: make test exited 0 after sync_base f4aa0348d7 and tested_head 2237c79b3a.
Impact: Task card text only. No code or gitlink change.
Refs: feature/agent-stack-blueprint
Co-authored-by: Cursor <cursoragent@cursor.com>

.task/feature-agent-stack-blueprint.md

@@ -24,5 +24,5 @@
 ## 结果与验证（完成后填写）
 
 - 结果：Documents `233dfb54ea1cd8e8085769832eef18fb3eaa04b7`。提案 `docs/proposals/2026-10-02-agent-stack-completion.md`，审计 `docs/records/2026-10-02-agent-stack-audit.md`。Documents PR https://git-home.u1680832.nyat.app:30319/weichen/Agent-System-Documents/pulls/34 。本分支推进 `modules/documents` 到该提交。
-- 验证：
+- 验证：启动 `make precheck` verdict READY，head `f4aa0348d7`（2026-10-02T16:20Z）。`make task-sync`：Already up to date。`[synced] sync_base=f4aa0348d7 tested_head=2237c79b3a checked_at=2026-10-02T16:30:55Z`。随后 `make test` 退出码 0：boundaries ok；core ok；backend 各包 ok（server 5.261s）；frontend vitest 13 文件 68 项；ui tsc 与 vitest 11 文件 79 项；agent-command 与 conformance ok。
 - 影响与剩余项：阶段 R0 起另开任务。`.task/feature-native-squad-full-upgrade.md` 是空卡且 worktree 已不存在，本次不处理，由所有者决定闭合或放弃。合入权在所有者。