Is it permissible to work as a linguistic proofreader for construction projects related to usurious banks, and is there sin or participation in usury in that? And if the papers have been submitted beforehand, is it necessary to request their retrieval?

You are not permitted to correct or improve matters related to usurious banks, as this constitutes participation in usury and assisting in it. Allah Almighty said: "And cooperate in righteousness and piety, but do not cooperate in sin and aggression." Furthermore, the Prophet, peace and blessings be upon him, cursed the one who consumes Riba, the one who pays it, its scribe, and its two witnesses. You must repent to Allah Almighty for what has passed, and if it is possible to retrieve it without harm, that is better; otherwise, seek Allah's forgiveness and do not return to it.