Reader navigation link and parity fix

This update makes it easier to discover what changed, and it tightens up a reader verification check to better match real layout alignment.

New in the reader

A shared “What’s new” action is now available in the reader navigation across web, Chrome, and Edge. It links directly to the hosted changelog, so you can quickly review recent updates without hunting for release notes.

Fixes

Reader parity verification now measures card actions against the padded content edge they align to. This corrects the reference point used during verification, helping parity checks reflect the intended UI alignment more accurately.