cron: type of cron that also notifies

It would be useful to know when some crons fire, such as the camera backup crons. If these fire, then the broadcast software has failed to turn the camera and the team should be warned.

No file, test, or entry point is named. First clarify which cron jobs need notification, how the team should be warned, and where cron scheduling and broadcast-software health are handled; done means the specified jobs reliably trigger the agreed warning when they fire.

Written by the indexing model from the issue text.