The controller's forge token never entered bao: the forge minted it in its
container, hive-forge-swarm-controller-token copied it to a host file, and the
controller LoadCredential'ed that file. forgeTokenFile defaulted to that path
only where the forge ran, so a controller on any other host had no forge
access unless an operator copied the file by hand.
Now the forge's host publishes it and the controller reads it:
- swarm-bao-forge-publisher (replaces hive-forge-swarm-controller-token)
waits for the in-container token, logs in with its own forge-publisher leaf
and writes it to swarm/controller/swarm-controller/forge/token. It runs on
every forge container start, the old unit's trigger.
- New principal swarm-forge-publisher: leaf minted by glue-bao-tls.nix,
policy create/update on that one path, written by
swarm-bao-forge-publisher-policy, CN reserved as a hive name.
- The controller policy gains read on that path. swarm-controller reads it
at start under its own certificate with the OIDC secret's retry, and runs
without forge access if it still cannot.
- forgeTokenFile, its LoadCredential and the forgeEnv gate are gone;
SWARM_CONTROLLER_FORGE_URL is always set. hostSwarmControllerTokenFile is
removed, and a tmpfiles rule deletes the old host copy on the forge host.
The in-container file stays: the mint unit's only-once guard reads it, and
it is the publisher's source.
Refs #4998