Confirm quitting zed if there is something running

[afgomez]

I think this can be a good usability improvement.

If there is something running from Zed like a long-running task, a debugger session, an agent execution, etc., and the user clicks the close button or presses ⌘+Q, the editor should ask for confirmation before quitting.

This can be a custom setting for people who don't want this behaviour.

[runofthemillgeek]

+1 since I also sometimes accidentally press press Cmd + Q and it's quite annoying right now without an option like confirm before quit from VSCode: https://code.visualstudio.com/updates/v1_67#_confirm-before-quit

I'll extend the original ask to also take into account unsaved changes in buffers. It could be something like this:

confirmBeforeClose: "off" | "keyboardOnly" | "workInProgress"

[benn-herrera]

Accidentally interrupting an agent set run because of a 'quit' shortcut in the wrong window is a real bummer and it's easy to do if you're a little tired or juggling tasks.

In the "not griping about an amazing piece of free software" department: Thank you for your work on Zed - it took me less than 120 seconds (literally!) to fall in love with it and make an immediate switch from VSCode and the JetBrains suite.