Misc bugfixes, AI hit retaliation

core/src/mindustry/entities/comp/UnitComp.java

@@ -263,6 +263,13 @@ abstract class UnitComp implements Healthc, Physicsc, Hitboxc, Statusc, Teamc, I
         return hittable();
     }
 
+    @Override
+    public void collision(Hitboxc other, float x, float y){
+        if(other instanceof Bullet bullet){
+            controller.hit(bullet);
+        }
+    }
+
     @Override
     public int itemCapacity(){
         return type.itemCapacity;

core/src/mindustry/entities/units/UnitController.java

@@ -6,6 +6,10 @@ public interface UnitController{
     void unit(Unit unit);
     Unit unit();
 
+    default void hit(Bullet bullet){
+
+    }
+
     default boolean isValidController(){
         return true;
     }