How can one deal with a mother who gets angry and invokes curses when there is a difference of opinion with her on life matters, and is being truthful with her considered an act of disobedience if it angers her?

It is forbidden to lie to a mother to gain her satisfaction. Lying to a mother is not permissible, even if she becomes angry because you disagree with her incorrect opinion. If a person is consulted on a matter, they must be a sincere and trustworthy advisor. If your advice, due to lying to her, results in harm, then you would be sinful. You have done well in striving to avoid your mother's anger by choosing the best approach. It is recommended to appease her and apologize gently, while ensuring that someone who has influence over her advises her to avoid interfering in discussions that might lead to problems for her, and to supplicate for her guidance and righteousness.