Add multi-row selection support with bulk editing

- Show "(Multiple values)" when selected rows have different values
- Allow bulk editing: changes apply to all selected rows
- Rename format to "Table - Row" for clarity

packages/web/src/widgets/CellDataWidget.svelte

@@ -16,7 +16,7 @@
     },
     {
       type: 'table',
-      title: 'Table',
+      title: 'Table - Row',
       component: TableCellView,
       single: false,
     },