[aide] 修复: aide flow finish 后工作目录不干净的问题

- 在 _merge_normal 方法中添加收尾提交
- record_branch_finish 更新 branches.json/md 后创建提交
- 确保 finish 完成后 git 仓库状态干净

.aide/branches.json

@@ -77,7 +77,9 @@
       "task_id": "2025-12-17T06-07-01",
       "task_summary": "测试",
       "started_at": "2025-12-17T06:07:01+08:00",
-      "status": "active"
+      "status": "finished",
+      "end_commit": "346ec90386190363cb71651e6bff3c64bb6b86f9",
+      "finished_at": "2025-12-17T06:07:50+08:00"
     }
   ]
 }

.aide/branches.md

@@ -6,8 +6,9 @@
 - **任务ID**: 2025-12-17T06-07-01
 - **源分支**: master
 - **起始提交**: 8d4cae6
-- **状态**: active
-- **时间**: 2025-12-17 06:07
+- **结束提交**: 346ec90
+- **状态**: finished
+- **时间**: 2025-12-17 06:07 ~ 06:07
 
 ## aide/006
 

.aide/flow-status.lock

@@ -1 +0,0 @@
-43517