In addition to that forum archive, here’s a Steam support response via Reddit: https://www.reddit.com/r/Games/comments/18mzcn/i_asked_steam_support_what_happens_to_my_games_if/
Gabe Newell has promised that if Steam goes down you won’t lose your library, but we only have his word as assurance.
Its been in Just Dance
You can log into the browser beforehand if that helps
I have Button Mapper trigger a Tasker task that locks my phone when I hold the volume down button, for some reason Button Mapper’s lock doesn’t trigger a lockdown.
(Tap and hold still lowers the volume)
Kagi lets you prioritize/demote/block per-domain but that’s a separate feature