What is the ruling on signing a contract that contains a clause of disbelief (kufr) or sin, with the intention of not abiding by this clause when the time for its implementation comes? And is this signature considered an acceptance of that, based on the hadith, "Any condition that is not in the Book of Allah, the Mighty and Exalted, is void"?

There is no objection to signing contracts that include a clause for arbitration by man-made courts or acceptance of man-made laws, if one dislikes and disapproves of this condition but is compelled to it by necessity. The widespread prevalence of such contracts in both Islamic and Western countries makes it difficult to avoid them, and when a matter becomes constrained, it expands to facilitate ease for people, based on the Almighty’s saying: "Allah intends for you ease and does not intend for you hardship," and His saying: "and has not placed upon you in religion any difficulty."