Bug 500842

SUMMARY
OSC 3008 is a new sequence that can be used to notify terminal emulators about any context changes.
Examples of such context changes are: Entering containers, gaining elevating privileges, or establishing a remote shell using SSH.

STEPS TO REPRODUCE
1. In bash, source https://github.com/systemd/systemd/blob/main/profile.d/80-systemd-osc-context.sh
2. (The above step installs a hook for the bash prompt, drawing the current prompt already emitted the sequence)

ADDITIONAL INFORMATION
The sequence is very new and being specified by systemd. When using the latest systemd from main, commands like systemd-vmspawn, machinectl shell, systemd-vmspawn and run0 already produce these sequences. The exact spec can be found here: https://github.com/systemd/systemd/blob/main/docs/OSC-CONTEXT.md

It would be very valuable if some of the maintainers would take a look at the spec and see if there are concerns/reservations about the current design from the view of KDE/Konsole. So far only the Ptyxis maintainer has chimed in. The spec is still fresh and malleable until a release happens. Currently the next expected release is a while away but the sooner there is feedback the easier it will be to incorporate it.

POSSIBLE USE CASES
- paint the background in dark red when running run0/sudo or blue when unvoking ssh
- setting the window title based on some of the emitted values (e.g. the "vm=..." and "container=..." fields)
- detecting the currently invoked command and working dir (while Konsole already scans them from /proc this would still be relevant where that is not accessible, i.e. Flatpak or Windows)
- provide some kind of shell-history minimap (similar to ones in IDEs) with colored regions to see where on was in a container etc
- provide bookmarks/jumps to previous context switches