Is it permissible for me to stop working unpaid overtime and adhere only to the official working hours stipulated in the contract, given the pressure from employers to demand increased production and the threat of salary deduction and retaliation against my wife at her workplace, knowing that my contract does not specify a production quota?

The reward for sincerity and excellence in work is the love of Allah, so do not be concerned with the displeasure of creatures if they demand what does not please Allah. Piety towards Allah brings sustenance and an exit from distress. It is not permissible for employers to threaten salary deductions while the agreed-upon time is being adhered to, because a contract based on duration necessitates the wage, and combining duration with the quantity of work increases the uncertainty (gharar) in the hiring agreement. The contract is based on time, not on the number of devices, and it is not permissible to compel the worker to finish devices for which there was insufficient time. A hiring contract is binding on both parties and cannot be revoked except by mutual consent.