The responder reads the callout xkey before it connects, so a responder
with no secret store no longer starts, and its "deny every agent token,
serve OIDC" mode could not run. That mode is gone: `agent_token::Store`
is built from the settings the xkey load already read, and `authorize`
takes a source rather than an `Option` of one.
On the nix side, `deploy.nats.authBaoClientCertFile` and
`authBaoClientKeyFile` are now asserted at eval when the queue is
enabled. The units' no-identity branches, the copy unit's empty-file
fallback and its "denies agent tokens" message are removed; an absent
leaf file fails `swarm-nats-auth-secrets` like an absent seed does.
The shared `hive` fixture turned `deploy.hive-controller.enable` on for
every eval test. It is now off by default; `hiveWithController` turns it
on, and the fixtures whose claims read the hive tier (hive-c0re, the
queue-agent credential, the hive leaf, `deploy.hive-controller.*`, or an
absence that is only meaningful with a hive present) use it.
glue-nats-auth-bao-identity.nix still read the renamed
`services.hyperhive.enable`, which printed the "Obsolete option" trace
six times per CI run. The term is dropped: the pairing is gated on the
queue and the minted PKI, as its sibling glue-nats-bao-identity.nix is.
An `auth_token` spelled `swarm-agent.<agent>.<secret>` is no longer sent
to introspection. The responder reads `swarm/agents/<agent>/queue` with
an identity of its own, checks that the stored object names the same
agent, compares the secret in constant time, and grants the subjects
`--agent-token-publish-subject` lists with `{agent}` expanded. Every
other outcome denies: a malformed token, no store identity, nothing
stored, a failed or slow lookup, a different secret. A token without
the prefix takes the OIDC path unchanged.
The journal's `auth request` line names such a caller `agent:<agent>`;
the hive-shared credential keeps `hive-<h>-agent`.
The new principal: a `swarm-nats-auth` cert-auth role and policy with
read on `secret/data/swarm/agents/+/queue` alone, a leaf signed by the
store's PKI glue, and `glue-nats-auth-bao-identity.nix` pairing the two.
The copy unit delivers the identity into the queue's container, and an
absent leaf is delivered empty so the responder still starts and only
agent tokens are refused.
The policy and role are written by `swarm-bao-nats-auth-policy`, logged in
as the bao granter: both names fall under its `swarm-*` globs, so the
deploy writes them with no operator step. module-eval counts it among the
granting units, so every generic granting-unit case covers it.
The secret compare uses `subtle`, already in the lock file through the
TLS stack; no workspace crate offered one directly.
