Refactor balance check in increaseReservedBalance method to delegate validation to the caller, improving clarity and responsibility separation.

src/card/services/account.service.ts

@@ -64,9 +64,8 @@ export class AccountService {
   }
 
   increaseReservedBalance(account: Account, amount: number) {
-    if (account.balance < account.reservedBalance + amount) {
-      throw new UnprocessableEntityException('CARD.INSUFFICIENT_BALANCE');
-    }
+    // Balance check is performed by the caller (e.g., transferToChild)
+    // to ensure correct account (guardian vs child) is validated
     return this.accountRepository.increaseReservedBalance(account.id, amount);
   }