Footnote Nav Hook Cleanup

Goal

Clean up apps/www/src/registry/ui/footnote-node.tsx by moving local navigation-highlight logic out of the app file and replacing as any access with typed plugin-driven access.

Scope

• move useNavigationHighlight(path) into core nav-feedback React code
• use typed getApi/getTransforms(FootnoteReferencePlugin) access in the footnote UI
• keep behavior unchanged

Outcome

• added useNavigationHighlight(path) in packages/core/src/react/plugins/navigation-feedback/useNavigationHighlight.ts
• exported it through the core React navigation-feedback barrel
• removed local useNavigationHighlight from apps/www/src/registry/ui/footnote-node.tsx
• replaced footnote api/tf as any access with typed helper access based on FootnoteConfig and FootnoteReferencePlugin
• switched element path reads to usePath() in the footnote UI

Verification

• pnpm brl
• bun test apps/www/src/registry/ui/footnote-node.spec.tsx
• pnpm turbo build --filter=./packages/core --filter=./packages/footnote
• pnpm turbo typecheck --filter=./packages/core --filter=./packages/footnote
• pnpm lint:fix