Stable now calls the desktop bundle workflow once per build group, and
each Mac arch and the Windows bundle assembly stage a <group>-receipt.json
into its attempt archive before the group's smoke runs. The receipts let
the next commit start each install arm from its own group's bytes.
publish-bundles and complete temporarily lose their candidate-manifest
digest source; the next commit moves that job into stable-release.yml and
wires the digest back.
107af642b2