Console UI could be extended to allow rich information to be shown when a runtime has not yet started.

[petetronic]

There are multiple scenarios where a valid runtime cannot be started for a session, and the Console is essentially dead in this state. We do have some basic initial state that prompts people to start a language runtime when none is currently running, but there are other states where the user will have to do some work before we could start any runtime.

While sending warnings in modals and toast notifications are one way to inform the user about an error state or an action they need to take, they are ephemeral and may be accidentally dismissed or not immediately actionable and then the details forgotten.

We should consider a way for the language runtime client system to send richer information to the console that could persist in the otherwise wasted screen real estate. The content could include information on how the user can get out of this state.

[juliasilge]

An example where we might like to use this ability includes #3468; the current proposed solution in #5671 uses an error from the notification service.

I may be misunderstanding but I don't think this would be a good fit for a problem like #5648 because in that case Python may well be starting and I don't believe we would want to use the console real estate; that's an R-specific situation ("you have R installed but we can't use it") that does seem to me like a good fit for a modal or toast.

[jmcphers]

As a sort of left-field idea, I wonder if it would make sense to have Python and R consoles as separate tabs in the Panel instead of putting everything under one Console tab. Then stuff that's about Python in general (or R in general) could go to their respective console tabs. Some folks might also prefer that R and Python sessions live in their own containers instead of being mixed together. What do you think?