ngx-ui-scroll 4.2.0 on Node.js NPM

What's Changed

Angular 21 compatibility update (library, demo app, tests, and tooling) by @dhilt in #365
Fixed item identity tracking to prevent Angular 21 warning NG0956 (track-by-identity full collection re-creation): rendering now uses stable item.uid, aligned with core identity persistence updates in vscroll
Added/updated adapter coverage to validate uid uniqueness and stability across mutations (update, append, prepend, clip, reset, reload, remove)
Updated core peer dependency requirement to vscroll@^1.8.3 (versions 1.8.0-1.8.2 are not supported in this release)

Full Changelog: v4.1.0...v4.2.0