fix: clear gameObjectDisplayIdFailedCache_ on world reset and zone change

The failed-model cache introduced in f855327 would persist across map
changes, permanently suppressing models that failed on one map but might
be valid assets on another (or after a client update). Clear it in the
world reset path alongside the existing gameObjectDisplayIdModelCache_
clear, so model loads get a fresh attempt on each zone change.

src/core/application.cpp

@@ -4113,6 +4113,7 @@ void Application::loadOnlineWorldTerrain(uint32_t mapId, float x, float y, float
 
         gameObjectInstances_.clear();
         gameObjectDisplayIdModelCache_.clear();
+        gameObjectDisplayIdFailedCache_.clear();
 
         // Force player character re-spawn on new map
         playerCharacterSpawned = false;