And then with nothing reported and no paper trail she sues them and wins.
But anyway, about the pay, if you already worked the hours, it's illegal to only pay you minimum wage in most states. And state law takes priority over any agreement that you made. So if it was illegal to lower your pay after you worked the hours, they'll be mailing you a check after you report them. Just make sure to call your department of labor tomorrow and ask about if they were allowed to do that. Make sure you specifically say that your pay was cut for hours you already worked. You cannot agree to something illegal. Even if you sign a contract. State law takes priority.
Don't listen to the people saying not to stand up for yourself. If you need a lawyer, get one. They're not going to tell a job that calls them that you took them to court.
If you can't stand up for yourself being accused of letting drugs go missing, or you can't stand up for yourself not being paid what you agreed to, you're going to get walked all over for your entire career.
And for applying for jobs, leave all of that out. You quit voluntarily and leave it at that. Don't say anything else. If they ask you about it, listen to the advice TriciaJ gave you. Don't bring up the narcotics. The ONLY time you should talk about what happened is if they somehow already know about it and ask you. If there's nothing filed with your state board, or police, it never happened. If it's true that you had nothing to do with it, they know that reporting it to the state is going to end up leading to them getting counter-sued by you and getting in a ton of trouble and easily getting some negative press. Most jobs, even if they fire you, they don't confirm how your employment ended. If you just quit, odds are all they're going to do is say that yes, you worked there during those dates. HR departments are VERY careful when they confirm employment, because if what you were fired for wasn't true, they just opened themselves up to be paying you a good amount of money in court. Until it's reported, you never stole those narcotics. And knowingly reporting you when you didn't steal them is libel and it's illegal. Relax. They need to be able to build a case that you were the one who did it.