Is it permissible for a wife to refuse her husband's marriage to another woman, especially if she feels wronged and that her rights and dignity have been lost?

You must repent and seek forgiveness for saying that the Sharia decreed eternal misery, because the law of Allah came to rectify people's conditions. It is Allah's law that permitted marriage to more than one woman, under strict conditions and profound wisdom. A husband's injustice does not justify resentment towards the Sharia; rather, it is due to the husband's shortcomings. You can resort to the Sharia court to compel him to provide maintenance and overnight stay. Polygyny is commanded by the Sharia, and it is impermissible to view it with disdain due to a husband's injustice. It is impermissible to insult or curse time, for Allah is Time and the changer of night and day. Furthermore, your statement that sexual friendship restores a woman's dignity, which was supposedly confiscated by the Sharia, is a dangerous statement that may lead to loss of faith; for adultery does not restore the dignity that the Sharia has preserved. Advise your husband to be just and to seek help from righteous people. If he insists on injustice, you have the right to seek separation through the Sharia court.