Nothing. You can't negotiate your way out of this.
In advance you tell her that going out and having this friend must end or you will be throwing her out, filing for divorce, ending our marriage or whatever words you want to use. Then, follow through with it such as by changing the locks, withdrawing financial support, or speaking to an attorney.
Basically, let her know there will be a consequence, let her make the choice, and then make the consequence reality if she makes the choice you do not want her to make.
please forgive me if this was already said,i didnt get a chance to read all replies as i dont have much time right now,but i agree with Hicks in a way.
but i would say something such as
"you know how i feel about your friend and why,im having trust issues due to your lies and hiding tghings from me and staying out to 4 in the morning is disrepectful to me and our marriage.
im asking you to limit your friendship with your friend and to stop going to bars/clubs as it leads to trouble and something married people should do together,not apart.
im unhappy the way things have been in our marriage the past couple months and im asking you to help me in fixing it and to stop the behavior that is hurting me.i been respectful and loving to you in our marriage and if you ask me to stop a behavior that was hurting,i would.
if you refuse to stop the behaviors that our hurting me and our marriage,i will take that as our marriage is not important to you and maybe we should seek a therpist or a separation were you would be the one staying somewere since you are the one not willing to work on us,as i refuse to be in a marriage were im being disrespected and were trust is an issue.
be firm and mean it if you say it though,be ready to follow through of letting her go.
give her a couple days to think about what you told her before the weekend comes,see what she does.
i wish you both the best