guard against a null view tag when keyboard-controller's
useExtraContentPadding flushes its deferred scrollTo. the rAF callback can
fire after the ScrollView detaches (navigating away, list re-creating its
scroll component), at which point scrollViewRef() is null. on the old arch
reanimated's scrollTo passes that null to the native _scrollToPaper
HostFunction, which throws "Value is null, expected a number".
re-check the ref inside the rAF before scrolling.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Samuel Newman