Runs a culling check every 200ms alongside the spring ticker.
Off-screen image sprites are hidden (visible=false), on-screen
ones get updateLOD() called with the current zoom level. Video
sprites get onVisibilityChange() to auto-play/pause based on
viewport visibility. Uses a 200px margin to avoid popping.
Implements the main React component wrapping PixiJS v8 Application and
pixi-viewport with: async init, viewport persistence per board,
space-to-pan, spring animation ticker, v1/v2 scene loading, ResizeObserver
resizing, and imperative handle (fitAll, zoom control, scene/viewport access).
Hiren Kangad