Replaces the dev/beta branch split with one trunk (main): dev-track
builds still publish on every push, but the beta track now publishes
from a vX.Y.Z-rc.N prerelease tag instead of a separately-maintained
beta branch. Removes the branch nobody reliably kept in sync.
Cargo.toml can drift stale relative to the actual last release (observed
on breadbox/breadpad/breadcrumbs/breadpaper), which made the auto-bumped
dev version sort as OLDER than what's already installed — bakery's semver
check correctly refused those "updates". Deriving the base version from
git ls-remote --tags instead is self-healing regardless of Cargo.toml
drift, with a Cargo.toml fallback only for a repo with no tags yet.
The fixed /tmp/bread-ecosystem-ci path races when multiple repos' dev/beta
workflows run close together on the same self-hosted runner — one job's
rm -rf/clone can stomp another's in-progress checkout, causing the
regenerate-index step to fail intermittently. Switch to mktemp -d.
Adds dev-release.yml (publishes on every push to dev) and beta-release.yml
(publishes on a beta-v* tag), mirroring the pattern landing in
bread-ecosystem/bread. Also creates the dev branch for this repo, which
didn't exist before — see bread-ecosystem/docs/release-channels.md for the
three-track policy.
