Battle simulator.

I've added all the spells, one way or another. To do this, I had to delve into almost all the class logic, but it was worth it. Temporarily, I've broken the functionality where casting a spell by a unit doesn't end the turn. The focus was more on implementing the spells themselves, and the rest can be fixed later. Unique unit attacks are not working yet, but with the new approach, their implementation is just a matter of time. I ask everyone interested to test it.