Add drag-and-drop reordering to upload preview

- Enable image reordering in MultiUploadPage before upload
- Add handleReorder callback to update local state
- Users can now sort preview images via drag-and-drop
- Upload order follows the sorted preview order
- No API call needed (pure local state management)

frontend/src/Components/Pages/MultiUploadPage.js

@@ -92,6 +92,12 @@ function MultiUploadPage() {
     });
   };
 
+  // Handle drag-and-drop reordering (only updates local state, no API call)
+  const handleReorder = (reorderedItems) => {
+    console.log('Reordering images in preview:', reorderedItems);
+    setSelectedImages(reorderedItems);
+  };
+
   const handleUpload = async () => {
     if (selectedImages.length === 0) {
       Swal.fire({
@@ -195,6 +201,8 @@ function MultiUploadPage() {
                   onDelete={handleRemoveImage}
                   mode="preview"
                   showActions={true}
+                  enableReordering={true}
+                  onReorder={handleReorder}
                 />
 
                 {selectedImages.length > 0 && (