refactor(explore): migrate Explore Controls from react-dnd to @dnd-kit (#37880)

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

superset-frontend/src/explore/components/controls/DndColumnSelectControl/DndMetricSelect.tsx

@@ -408,6 +408,9 @@ const DndMetricSelect = (props: any) => {
     multi ? 2 : 1,
   );
 
+  // Generate sortable type that matches MetricDefinitionValue's type
+  const sortableType = `${DndItemType.AdhocMetricOption}_${props.name}_${props.label}`;
+
   return (
     <div className="metrics-select">
       <DndSelectLabel
@@ -418,6 +421,8 @@ const DndMetricSelect = (props: any) => {
         ghostButtonText={ghostButtonText}
         displayGhostButton={multi || value.length === 0}
         onClickGhostButton={handleClickGhostButton}
+        sortableType={sortableType}
+        itemCount={value.length}
         {...props}
       />
       <AdhocMetricPopoverTrigger