Channels:
stable -> branch main (open, no key)
beta -> branch beta (release candidate, key-gated)
dev -> branch dev (active development, key-gated)
beta and dev require PHOBOS_KEY (subscriber key distributed via Boosty);
only the sha256 hash is embedded in install.sh / update.sh. stable stays
open. install.sh honours CHANNEL=stable|beta|dev; phobos-update accepts
stable|beta|dev|<tag> and gates the closed channels. --check now lists all
three channels with a [закрыт ключом] marker.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
