Is the wife entitled to claim the value of her gold which she sold of her own free will to contribute to the purchase of a house, and then later claimed that it was a trust with the husband, and the court rejected her claim after the husband took an oath?

There is no objection to this قسم (oath/division) if you took the money with the wife's consent, and your liability is cleared, and she has no right to demand it back if she gave it as a donation and of her own free will. However, if the wife gave it out of fear of your anger, then she has the right to demand it back according to some scholars, and the more cautious approach is to return it to her.