He says: Is it permissible for a sane, mature woman to dispose of her wealth without her husband's permission? And what is the authenticity of the narrations that prohibit her from disposing of her wealth without her husband's permission?

The correct view is that she should not dispose of it without her husband's permission.

In the two authentic collections, there is a narration from Aisha, may Allah be pleased with them both, that the Prophet ﷺ gave advice to the women.

On the day of Eid, and he encouraged us to give charity.

So I would give charity from their jewelry without the husband's permission.

And as for the narrations that have been reported, they are either abrogated as has been said, or weak.

That is, from the narrations that mention forbidding her from giving charity without her husband's permission.