fix: clamp stats between 0 and max value

src/main/java/uulm/teamname/marvelous/gamelibrary/entities/Stat.java

@@ -33,11 +33,11 @@ public class Stat {
     }
 
     public void increaseValue(int value) {
-        this.value += value;
+        this.value = Math.min(this.max, this.value + value);
     }
 
     public void decreaseValue(int value) {
-        this.value -= value;
+        this.value = Math.max(0, this.value - value);
     }
 
     public int getMax() {