No, it does not mean money. A fiduciary duty is a duty to manage money in someone else's best interests.

It's confusing because "fiduciary" sounds like you have to optimize for the mercenary interests of shareholders, but that is not true. Not every corporation is founded to turn a profit; what do you think the fiduciary duty looks like for a nonprofit?

The general obligation for the company to behave morally comes from two places: specific laws and the fact that its employees want to sleep at night. These are more powerful than a lot of people want to give credit for.