Channels and promotion

Fleets follow a channel: stable, beta, whatever you name. Promoting a release to a channel is what makes containers move; they pick it up on their next check-in. stable cannot be deleted, and a channel a fleet follows must be freed before it can be removed.

Promote now, or schedule it: pick a time and the console promotes then. Scheduled promotions are listed on the app and can be cancelled until they run.

A channel can carry environment variables. They are pinned at promotion and travel with it, so editing the channel changes nothing until the next promotion. A fleet can override any of them by name, and fleet variables apply live. FLEETWIDE_* names are reserved for the supervisor.