Function commitPointsGeometry

Synchronous GPU commit step for a points node. Same behavior as the inline updatePointsGeometry:

• early return if the rootGroup or the named THREE.Points is gone,
• log + zero visiblePointCount on an empty-data frame,
• GPU-buffer-pool path (zero alloc on reuse) when the pool is set,
• dispose + recreate via nodeFactory.createPointsGeometry otherwise (the factory owns all dtype/bounds logic).