5k loss is a good lesson to remind you that you can't call everyone that you get close to as "friends"
Real friends are a fucking investment that pays dividends. This mothefucker isn't one of them. He fucked you from the start. He was never a friend to begin with.
5k is nothing in this climate. the legal fees arent worth. Consider it a cheap lesson and that you dodge a bullet. The longer you spend time with this cancer, the worse it gets. Go find new people. if you're a good enough software dev, you'll be fine.
If you can, lock him out of the website, shopify, or anything else you have access to that you're paying for.
cause building is cheap, with ai its going to get cheaper. The money is in the marketing and sales and ux