docs: 同步 task_archive 到架构文档

docs/en/architecture.md

@@ -242,7 +242,8 @@ def main():
 - `persona_update` - Update persona
 - `persona_clear` - Clear persona
 
-### Task Tools (5)
+### Task Tools (6)
+| `task_archive` | Archive completed/expired tasks | Step 6 mandatory, writes completion summary |
 | `task_query` | Query recent task list | Call first in new conversations to avoid duplicate tasks |
 - `task_create` - Create task
 - `task_set_state` - Set state

docs/zh/architecture.md

@@ -248,7 +248,8 @@ def main():
 - `persona_update` - 更新人设
 - `persona_clear` - 清除人设
 
-### 任务工具 (5个)
+### 任务工具 (6个)
+| `task_archive` | 归档已完成/过期的任务 | 步骤6强制执行，写入完成摘要 |
 | `task_query` | 查询最近任务列表 | 新对话时优先调用，避免重复创建任务 |
 - `task_create` - 创建任务
 - `task_set_state` - 设置状态