fix(Core/Combat): Fix guardians not attacking after threat system port (#25157)

Co-authored-by: blinkysc <blinkysc@users.noreply.github.com>

src/server/game/AI/CreatureAI.cpp

@@ -239,14 +239,16 @@ void CreatureAI::EnterEvadeMode(EvadeReason why)
     {
         if (Unit* owner = me->GetCharmerOrOwner())
         {
+            // Owned creatures (pets/guardians) follow their owner — clear evade state
+            // so they can re-enter combat immediately via CanBeginCombat
+            me->ClearUnitState(UNIT_STATE_EVADE);
             me->GetMotionMaster()->Clear(false);
             me->GetMotionMaster()->MoveFollow(owner, PET_FOLLOW_DIST, me->GetFollowAngle(), MOTION_SLOT_ACTIVE);
         }
         else
         {
             // Required to prevent attacking creatures that are evading and cause them to reenter combat
-            // Does not apply to MoveFollow
+            // Does not apply to MoveFollow — UNIT_STATE_EVADE is already set from _EnterEvadeMode
-            me->AddUnitState(UNIT_STATE_EVADE);
             me->GetMotionMaster()->MoveTargetedHome();
         }
     }
@@ -381,8 +383,11 @@ bool CreatureAI::_EnterEvadeMode(EvadeReason /*why*/)
         return false;
     }
 
-    // Set evade state early to prevent recursion when CombatStop triggers JustExitedCombat
+    // Set evade state early to prevent recursion: CombatStop below purges combat
-    // This will be cleared in MoveTargetedHome for pets/guardians following their owner
+    // refs, which triggers JustExitedCombat -> EnterEvadeMode -> _EnterEvadeMode.
+    // The IsInEvadeMode() check above will catch it.
+    // EnterEvadeMode will clear this for owned creatures (pets/guardians) that
+    // use MoveFollow instead of MoveTargetedHome.
     me->AddUnitState(UNIT_STATE_EVADE);
 
     // don't remove vehicle auras, passengers aren't supposed to drop off the vehicle

src/server/game/Entities/Unit/Unit.cpp

@@ -7333,19 +7333,22 @@ bool Unit::Attack(Unit* victim, bool meleeAttack)
     // set position before any AI calls/assistance
     //if (IsCreature())
     //    ToCreature()->SetCombatStartPosition(GetPositionX(), GetPositionY(), GetPositionZ());
-    if (creature && !IsControlledByPlayer())
+    if (creature)
     {
         EngageWithTarget(victim);
 
-        creature->SendAIReaction(AI_REACTION_HOSTILE);
+        if (!IsControlledByPlayer())
+        {
+            creature->SendAIReaction(AI_REACTION_HOSTILE);
 
-        /// @todo: Implement aggro range, detection range and assistance range templates
+            /// @todo: Implement aggro range, detection range and assistance range templates
-        if (!(creature->HasFlagsExtra(CREATURE_FLAG_EXTRA_DONT_CALL_ASSISTANCE)))
+            if (!(creature->HasFlagsExtra(CREATURE_FLAG_EXTRA_DONT_CALL_ASSISTANCE)))
-            creature->CallAssistance();
+                creature->CallAssistance();
 
-        creature->SetAssistanceTimer(sWorld->getIntConfig(CONFIG_CREATURE_FAMILY_ASSISTANCE_PERIOD));
+            creature->SetAssistanceTimer(sWorld->getIntConfig(CONFIG_CREATURE_FAMILY_ASSISTANCE_PERIOD));
 
-        SetUInt32Value(UNIT_NPC_EMOTESTATE, EMOTE_ONESHOT_NONE);
+            SetUInt32Value(UNIT_NPC_EMOTESTATE, EMOTE_ONESHOT_NONE);
+        }
     }
 
     // delay offhand weapon attack by 50% of the base attack time

src/server/scripts/Pet/pet_dk.cpp

@@ -306,6 +306,8 @@ struct npc_pet_dk_army_of_the_dead : public AggressorAI
 {
     npc_pet_dk_army_of_the_dead(Creature* creature) : AggressorAI(creature) { }
 
+    // Restrict MoveInLineOfSight aggro to targets already fighting our owner,
+    // so ghouls don't pull extra packs on their own.
     bool CanAIAttack(Unit const* target) const override
     {
         if (!target)
@@ -315,6 +317,26 @@ struct npc_pet_dk_army_of_the_dead : public AggressorAI
             return false;
         return AggressorAI::CanAIAttack(target);
     }
+
+    // Owner started attacking a target — engage immediately.
+    // We bypass OnOwnerCombatInteraction because CanStartAttack -> CanAIAttack
+    // may reject the target before combat refs are established.
+    void OwnerAttacked(Unit* target) override
+    {
+        if (!target || !me->IsAlive() || me->HasReactState(REACT_PASSIVE))
+            return;
+        if (me->IsValidAttackTarget(target))
+            AttackStart(target);
+    }
+
+    // Owner was attacked — help defend.
+    void OwnerAttackedBy(Unit* attacker) override
+    {
+        if (!attacker || !me->IsAlive() || me->HasReactState(REACT_PASSIVE))
+            return;
+        if (me->IsValidAttackTarget(attacker))
+            AttackStart(attacker);
+    }
 };
 
 struct npc_pet_dk_dancing_rune_weapon : public NullCreatureAI