Handle SMSG_GAMEOBJECT_CUSTOM_ANIM to unfreeze gameobjects on use

When the server sends a custom animation packet (e.g. chest being
opened), unfreeze the M2 instance so it plays its open animation.

include/game/game_handler.hpp

@@ -593,6 +593,9 @@ public:
     using GameObjectDespawnCallback = std::function<void(uint64_t guid)>;
     void setGameObjectDespawnCallback(GameObjectDespawnCallback cb) { gameObjectDespawnCallback_ = std::move(cb); }
 
+    using GameObjectCustomAnimCallback = std::function<void(uint64_t guid, uint32_t animId)>;
+    void setGameObjectCustomAnimCallback(GameObjectCustomAnimCallback cb) { gameObjectCustomAnimCallback_ = std::move(cb); }
+
     // Faction hostility map (populated from FactionTemplate.dbc by Application)
     void setFactionHostileMap(std::unordered_map<uint32_t, bool> map) { factionHostileMap_ = std::move(map); }
 
@@ -1401,6 +1404,7 @@ private:
     GameObjectSpawnCallback gameObjectSpawnCallback_;
     GameObjectMoveCallback gameObjectMoveCallback_;
     GameObjectDespawnCallback gameObjectDespawnCallback_;
+    GameObjectCustomAnimCallback gameObjectCustomAnimCallback_;
 
     // Transport tracking
     struct TransportAttachment {

src/core/application.cpp

@@ -1548,6 +1548,18 @@ void Application::setupUICallbacks() {
         despawnOnlineGameObject(guid);
     });
 
+    // GameObject custom animation callback (e.g. chest opening)
+    gameHandler->setGameObjectCustomAnimCallback([this](uint64_t guid, uint32_t /*animId*/) {
+        auto it = gameObjectInstances_.find(guid);
+        if (it == gameObjectInstances_.end() || !renderer) return;
+        auto& info = it->second;
+        if (!info.isWmo) {
+            if (auto* m2r = renderer->getM2Renderer()) {
+                m2r->setInstanceAnimationFrozen(info.instanceId, false);
+            }
+        }
+    });
+
     // Charge callback — warrior rushes toward target
     gameHandler->setChargeCallback([this](uint64_t targetGuid, float tx, float ty, float tz) {
         if (!renderer || !renderer->getCameraController() || !gameHandler) return;

src/game/game_handler.cpp

@@ -2259,6 +2259,16 @@ void GameHandler::handlePacket(network::Packet& packet) {
         case Opcode::SMSG_GAMEOBJECT_PAGETEXT:
             handleGameObjectPageText(packet);
             break;
+        case Opcode::SMSG_GAMEOBJECT_CUSTOM_ANIM: {
+            if (packet.getSize() >= 12) {
+                uint64_t guid = packet.readUInt64();
+                uint32_t animId = packet.readUInt32();
+                if (gameObjectCustomAnimCallback_) {
+                    gameObjectCustomAnimCallback_(guid, animId);
+                }
+            }
+            break;
+        }
         case Opcode::SMSG_PAGE_TEXT_QUERY_RESPONSE:
             handlePageTextQueryResponse(packet);
             break;