fix(thumbnail): [PKG-TOOL-THUMB-03] own input resources and separate sheet export

refactor/tasks.json

@@ -3785,11 +3785,14 @@
         "PKG-TOOL-THUMB-02",
         "CORE-01"
       ],
-      "status": "todo",
+      "status": "doing",
       "risk": "H",
       "deliverable": "输入、抽帧队列、网格导出、URL/监听清理分离",
       "acceptance": "结构变化和缺陷修复分开记录；原 API/事件/资源生命周期通过",
-      "evidence": []
+      "evidence": [
+        "changes/2026-09-13-PKG-TOOL-THUMB-03-input-checkpoint.md",
+        "baselines/thumbnail-input-checkpoint.json"
+      ]
     },
     {
       "id": "PKG-TOOL-THUMB-04",