Pull siege engine aggro on damage only

A siege engine switches to whoever damages it, player or pet, even when
it already has a target. Pre-roll melee retaliation, harmful-power
direct aggro (which also fires on misses) and Taunt no longer change a
siege engine's target. The attack timer is untouched, so a switched
engine still waits for its next cycle before firing.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/engine/gameManager/CombatManager.java

@@ -257,7 +257,8 @@ public enum CombatManager {
 
 
             //handle retaliate
-            if (AbstractCharacter.IsAbstractCharacter(target)) {
+            //siege engines only retaliate on damage, see AbstractCharacter.modifyHealth
+            if (AbstractCharacter.IsAbstractCharacter(target) && !(target.getObjectType().equals(mbEnums.GameObjectType.Mob) && ((Mob) target).isSiege())) {
                 if (((AbstractCharacter) target).combatTarget == null || !((AbstractCharacter) target).combatTarget.isAlive()) {
                     ((AbstractCharacter) target).combatTarget = attacker;
                     if (target.getObjectType().equals(mbEnums.GameObjectType.PlayerCharacter) && ((AbstractCharacter) target).isCombat())