How can I please Allah and my wife, and ensure she receives her rightful share of gold, especially since I don't accurately recall the value of each of our contributions to its purchase? And is her use of the car, her going to Hajj, and giving her 200 grams of 21-carat gold sufficient to fulfill her right?

The share contributed by the wife, whether in the apartment or in gold, is her exclusive right. She owns the amount she contributed as an undivided share in the apartment. The husband can purchase her share for an amount they agree upon, or her right must be proven. As for gold, if the amount is forgotten and there is no evidence, she should be given what she claims. Whatever was legally given to her during your lifetime and sound mind, and she took possession of it, is her private property. Merely writing the apartment in her name without transferring ownership during your lifetime, but rather for her to take possession of it after your death, is considered a will. A will in favor of an heir is not valid unless the other heirs agree.