Application-root configuration cascade for the sidenav family. Pass any
combination of withSidenavDimensions, withSidenavResponsive,
withSidenavShortcut, withSidenavHoverDwell, and withSidenavRouterSync
features in bootstrapApplication's providers array.
Resolution priority (high -> low):
Per-instance Input binding.
provideSidenavConfigAt(...) in a parent component's viewProviders.
provideSidenavConfig(...) at the application root.
Library defaults (CNGX_SIDENAV_DEFAULTS).
The provider deep-merges supplied features with the library defaults so
consumers only declare keys they want to override.