This is a proposal by people funded by companies that would provide the services for this (https://balkaninsight.com/2023/09/25/who-benefits-inside-the-eus-fight-over-scanning-for-child-sex-content ).
A lot of actual politicians oppose this https://tbbacherle.eu/2024/06/18/open-letter/
Oh I dunno, maybe something with almost 700 comments? (HDR).
If apps don't want to save their state when they close there isn't much a window manager can do about that. The only part the window manager would be involved in is with positioning its window and that is hardly something very critical to the functionality of an app.