Port to WoW client 12.0.7 (build 68453)

Adapt CypherCore from 11.2.5.63796 to 12.0.7.68453 using TrinityCore as
byte-exact reference.

- Fase 1: build gate 68453 (build_info + build_auth_key SQL, keys from TC)
- Fase 2: Opcodes.cs remapped by name to 12.0.7 values
- Fase 3: 32 DB2 structs + HotfixDatabase.cs SELECTs realigned; fixed
  ReputationManager/SpellInfo refs
- Fase 4: UpdateFields ported (GameObject/Conversation/AreaTrigger/Player/
  Unit/ActivePlayer + nested VisibleItem/QuestLog/BitVectors/CraftingOrderItem/
  SkillInfo)
- Critical protocol fixes: CreateObject header +3 bits (Room/Decor/MeshObject);
  EntityFragment enum renumbered to 12.0.7 (was 11.2.5 values, breaking every
  object packet)
- New-entity foundation: TypeId/TypeMask/HighGuid.MeshObject, fragment tags
- MeshObject entity scaffold (Midnight features are wire-format only)

Builds clean (dotnet build -c Release, 0 errors).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Source/Game/Maps/Map.cs

@@ -3579,6 +3579,11 @@ namespace Game.Maps
             return _objectsStore.LookupByKey(guid) as SceneObject;
         }
 
+        public MeshObject GetMeshObject(ObjectGuid guid)
+        {
+            return _objectsStore.LookupByKey(guid) as MeshObject;
+        }
+
         public Conversation GetConversation(ObjectGuid guid)
         {
             return (Conversation)_objectsStore.LookupByKey(guid);