Scary failure messages when shutting down the system while the Unsafe Browser is still running

I guess we should forcefully run the Unsafe Browser teardown code at shutdown time, if we don’t find anything more clever.

Feature Branch: bugfix/12354-drop-kexec-memory-wipe

Original created by @intrigeri on 8124 (Redmine)

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information