fix(Core/Vehicles): defer accessory init to avoid double install (#25486)

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/server/game/Entities/Creature/Creature.cpp

@@ -713,6 +713,13 @@ void Creature::Update(uint32 diff)
             m_vehicleKit->Reset();
     }
 
+    if (_triggerVehicleKitInit)
+    {
+        _triggerVehicleKitInit = false;
+        if (m_vehicleKit)
+            m_vehicleKit->Reset();
+    }
+
     switch (m_deathState)
     {
         case DeathState::JustRespawned:
@@ -1113,9 +1120,10 @@ bool Creature::AIM_Initialize(CreatureAI* ai)
     IsAIEnabled = true;
     i_AI->InitializeAI();
 
-    // Xinef: Initialize vehicle if it is not summoned!
-    if (GetVehicleKit() && m_spawnId)
-        GetVehicleKit()->Reset();
+    // Defer vehicle kit init to the next Creature::Update tick so accessories
+    // install after visibility sync.
+    if (GetVehicleKit())
+        _triggerVehicleKitInit = true;
     return true;
 }
 

src/server/game/Entities/Creature/Creature.h

@@ -536,6 +536,9 @@ private:
     // Formation variable
     CreatureGroup* m_formation;
     bool TriggerJustRespawned;
+    // Deferred vehicle init: set in AIM_Initialize, consumed on the next
+    // Creature::Update tick so accessories install after visibility sync.
+    bool _triggerVehicleKitInit = false;
 
     // Shared timer between mobs who assist another.
     // Damaging one extends leash range on all of them.

src/server/game/Maps/Map.cpp

@@ -346,11 +346,6 @@ bool Map::AddToMap(T* obj, bool checkTransport)
     //also, trigger needs to cast spell, if not update, cannot see visual
     obj->UpdateObjectVisibility(true);
 
-    // Xinef: little hack for vehicles, accessories have to be added after visibility update so they wont fall off the vehicle, moved from Creature::AIM_Initialize
-    // Initialize vehicle, this is done only for summoned npcs, DB creatures are handled by grid loaders
-    if (obj->IsCreature())
-        if (Vehicle* vehicle = obj->ToCreature()->GetVehicleKit())
-            vehicle->Reset();
     return true;
 }