Is the fine imposed on the company manager for delaying the payment of salaries considered usury (riba) and unlawful (haram), or is it a legitimate punishment aimed at safeguarding employees' rights and deterring managers from being lax in performing their duties, like a penalty clause?

It is not permissible to delay employees' salaries beyond their due date. If they are delayed, they become a debt, and it is not permissible to stipulate a financial penalty for their delay, as that would be usury (riba). Similarly, it is not permissible for the employee to demand compensation for the delay, but it is permissible for him to file a complaint to obtain the principal amount of the debt. The procrastinating debtor shall bear the costs of the lawsuit and whatever expenses the creditor incurred to collect his right.