Concerns: pushword/admin, pushword/core, pushword/newsletter
New sites no longer receive media/repurpose-nord.mp4, a 7 MB development video with no media entry. A site created from 1.0.76 on can delete that file unless its media library lists it.
Since 1.0.76 every started session was saved before its controller ran, and Symfony then silently skips migrate() and invalidate(). Only /admin requests are saved early now; login, logout and site controllers keep their session open. Nothing to do.
The newsletter screens' styles and scripts left the admin bundle for /bundles/pushwordnewsletter/admin.css and admin.js, loaded by the newsletter layout only. Sites serving copied bundle assets: refresh them with assets:install; installations using symbolic links need no refresh.