feat: implement bulk account deletion and enhance account management with folder organization and drag-and-drop functionality

services/account.service.ts

@@ -70,4 +70,11 @@ export const accountService = {
       where: { id },
     });
   },
+
+  async deleteMany(ids: string[]): Promise<void> {
+    // Transactions will be deleted automatically due to onDelete: Cascade
+    await prisma.account.deleteMany({
+      where: { id: { in: ids } },
+    });
+  },
 };