renderError

Shared "this render is broken" marker. visibleError(entityId) swaps an entity to the builtin ERROR text model + error material, so a failed render reads as an unmistakable 3D "ERROR" sign on screen instead of empty pixels — empty silently reads as "fine" and a broken object gets mistaken for working.

Every render component (built-in Model / SkinnedModel, or a user-authored one) calls this, so the error model is defined in one place: change it here and every render component updates.