How can one differentiate between a wet dream and the act of masturbation during sleep, especially when ejaculation occurs after reciting Ayat al-Kursi and seeking refuge in Allah before sleep with the intention of repentance?

As long as a person does not recall intentionally engaging in an act that caused the emission, there is no sin upon them. This is considered a wet dream, and the pen is lifted from the sleeper. One must beware of the whispers of Satan, which delude a person into believing they are the cause, in order to lead them to despair. The door of repentance is always open, and Allah forgives all sins for those who repent. Allah Almighty says: "And He it is who accepts repentance from His servants and pardons sins, and He knows what you do."