Is a wife who sought divorce (khulʿ) required to return the dowry and the jewelry to her husband, considering that the dowry was spent on household furniture and the jewelry (gold) is still in her possession?

If the khul' was performed based on an agreement to return the full mahr, then you must return the thirty thousand Egyptian pounds that your husband paid you as mahr. You are not obligated to return the gold or furniture that you purchased with some of the mahr. However, if the furniture and gold were the mahr paid, then you must return what remains of them. To determine the precise legal ruling, it is advisable to consult trustworthy scholars in your country directly.