refactor(Core/Combat): Port TrinityCore heap-based threat system (#24715)

Co-authored-by: blinkysc <blinkysc@users.noreply.github.com>
Co-authored-by: Treeston <treeston.mmoc@gmail.com>
Co-authored-by: killerwife <killerwife@gmail.com>
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

src/server/game/Server/WorldSession.cpp

@@ -628,7 +628,7 @@ void WorldSession::LogoutPlayer(bool save)
         //FIXME: logout must be delayed in case lost connection with client in time of combat
         if (_player->GetDeathTimer())
         {
-            _player->getHostileRefMgr().deleteReferences(true);
+            _player->GetThreatMgr().RemoveMeFromThreatLists();
             _player->BuildPlayerRepop();
             _player->RepopAtGraveyard();
         }