What is the ruling regarding a husband who swore that his wife would stay at her family's house for the rest of her life if she went there without his permission, knowing that he only intended to threaten her and fears that she might go again without his knowledge, and that he does not prevent her from going if she asks for permission?

What you swore upon was merely a promise that your wife would stay with her family for the rest of her life if she went to them without your permission. If she went and you did not fulfill your promise, then an expiation for a broken oath (kaffarat yamin) becomes obligatory upon you, and no divorce occurs, because you did not swear by it. If you did not intend a promise, then your statement is a metaphor (kinayah) for divorce and does not take effect except with intention, and you mentioned that you intended a threat, not a divorce. It is sufficient for you to break your oath and pay the expiation for an oath before breaking it. Your oath will be dissolved after the expiation, and you will not break your oath by not keeping your wife at her family's home if she goes without your permission.