/**
 * Helper component that invalidates during loading in frameloop="demand" mode.
 *
 * In "demand" mode, r3f only renders when invalidate() is called. However,
 * components like DreiSplat use useFrame internally for async operations
 * (e.g., Worker-based sorting). Without periodic invalidation during loading,
 * useFrame callbacks won't execute and the scene won't update.
 *
 * This component:
 * 1. Detects loading state via drei's useProgress (which listens to THREE.DefaultLoadingManager)
 * 2. Calls invalidate() every 100ms while loading is active
 * 3. Continues for 2 seconds after loading completes to allow async processing to finish
 */
export declare function LoadingInvalidator(): any;