To fix a regression where animateVisuals state is lost or listeners are not attached due to lazy loading of the Grid, we will introduce a Neo.state.Provider.

1. Create apps/devindex/view/ViewportStateProvider.mjs with animateVisuals: true.
2. Add the provider to DevIndex.view.Viewport.
3. Bind GridContainer's animateVisuals config to the state provider: bind: {animateVisuals: data => data.animateVisuals}.
4. Update MainContainerController (checkbox) to write to the state provider instead of the grid directly.
5. Update ViewportController to listen to the state provider changes to update the HeaderCanvas pulse effect, removing the direct dependency on the Grid component.