The HOST's loader manager (a LuxarApp's is
SceneLoaderManager.getInstance(); every LuxarLayer owns its own). The new
loader is registered there and inherits the host wiring the manager
carries — profiler, monitor and LOD-registry factories, render wake-up,
depth-sort coordinator — so two hosts on one page never share a loader.
URL or path to the Zarr store
Optionalconfig: LoaderConfig
Optional loader configuration
Optional ID to register the created SceneLoader under (default: 'default')
Promise resolving to a THREE.Group containing the scene
Load a complete scene from a Zarr store.
This is the main entry point for SceneLoader-backed loading.