createNativePlatformViewId

Returns a fresh, unique id for one native/embedded view of this onboarding.

Call it once per view instance and keep the result for that view's lifetime: the id keys both the per-view events observer and the native view manager, so two views sharing an id would overwrite each other's observer and misroute events. Deriving it from id alone is not enough — the same onboarding can be embedded more than once.