Notification on build failure

I often have the backpack dev process running in the background, it'd be awesome to get a native notification when a build fails due to whatever errors so that I know something's wrong 👌

No files, tests, or entry points are named. Start by locating Backpack's development-process and build-error handling, then determine how the project can expose failures to a native notification system. Done means a documented, supported behavior that notifies users when a background build fails.

Written by the indexing model from the issue text.