chore(backlog): 记录 g312 完成

.ua/backlog.json

@@ -3198,7 +3198,7 @@
     {
       "id": "g312",
       "domain": "tune",
-      "status": "open",
+      "status": "done",
       "title": "表格空状态补操作出口：真没数据时只能干看着",
       "motivation": "emptyRow 只区分「筛掉了」与「真没数据」，但两种情况都只给文案——列表本来就空时没有「新建」这类下一步，用户只能自己找工具栏；而筛选没结果时又该引导清条件，两种语义不该共用一个按钮位。",
       "acceptance": "① DataTableProps 新增 emptyAction 插槽，只在「真没数据」时渲染在占位文案右侧；② 有筛选词时该位置仍是「清除筛选」，两者互斥；③ manifest 参数表与手把手、类型注释同步；④ npm run check 全绿。",

.ua/iterations.log

@@ -356,3 +356,4 @@
 {"ts":"2026-10-27T00:39:08+08:00","id":"g309","result":"done","commit":"ae105b6","summary":"新增 ua iter done/add：留痕与补条目由 CLI 保证字段、时区与状态，删掉两个临时脚本"}
 {"ts":"2026-10-27T00:40:53+08:00","id":"g310","result":"done","commit":"be169b3","summary":"multiSelect 新增 selectAll：三态全选行 + 只作用于过滤结果 + 到 max 补满即停 + 键盘可达"}
 {"ts":"2026-10-27T00:41:42+08:00","id":"g311","result":"done","commit":"f794475","summary":"骨架文本高度改用字号×行高计算，与正文行盒等高，表格加载完成不再跳高"}
+{"ts":"2026-10-27T00:43:13+08:00","id":"g312","result":"done","commit":"c966550","summary":"dataTable 新增 emptyAction：真没数据时才渲染操作，有筛选词仍给清除筛选"}