fix(01): align image upload field name and wrap category delete in transaction

src/server/services/category.service.ts

@@ -63,14 +63,15 @@ export function deleteCategory(
     return { success: false, error: "Category not found" };
   }
 
-  // Reassign items to Uncategorized (id=1), then delete
-  // Use a transaction for atomicity
-  db.update(items)
-    .set({ categoryId: 1 })
-    .where(eq(items.categoryId, id))
-    .run();
+  // Reassign items to Uncategorized (id=1), then delete atomically
+  db.transaction(() => {
+    db.update(items)
+      .set({ categoryId: 1 })
+      .where(eq(items.categoryId, id))
+      .run();
 
-  db.delete(categories).where(eq(categories.id, id)).run();
+    db.delete(categories).where(eq(categories.id, id)).run();
+  });
 
   return { success: true };
 }