Factory hook that supplies a per-loader LODGroupRegistry. Mirrors
SceneLoaderMonitorFactory — the data/ layer never reaches into
scene/ for camera / viewport state, so the host (typically the app
pipeline) injects a closure that knows how to construct the
registry with proper getters. Receives the OWNING loader (as the
narrow LODGroupRegistryOwner view) so per-loader deps read
that loader's live state, not the manager's current default.
Factory hook that supplies a per-loader
LODGroupRegistry. MirrorsSceneLoaderMonitorFactory— the data/ layer never reaches into scene/ for camera / viewport state, so the host (typically the app pipeline) injects a closure that knows how to construct the registry with proper getters. Receives the OWNING loader (as the narrow LODGroupRegistryOwner view) so per-loader deps read that loader's live state, not the manager's current default.