`glue-matrix-bao-token.nix` has read
`secret/swarm/hives/<hive>/matrix/appservice-token` since it landed, but
nothing ever wrote that path. The store was empty in every deployment, so
every read degraded to "keep what activation minted" and each hive stayed
the origin of a value the swarm has to agree on — two hives never
converged.
`swarm-secret-publish` is now the producer. It already holds a store
identity, already writes under the hive prefix, and already runs per
hive in the roster, so the mint is a third loop beside the two OIDC
copies rather than a second shape of this unit.
Idempotence comes from a record of its own, not from the store: this
principal is granted `create`/`update` with no `read`, so it cannot ask
whether a hive already has a token. It keeps what it minted under
`StateDirectory=` (0700 dir, 0600 file) and mints only when that file is
missing or empty; the `put` runs every time, because re-putting the same
bytes changes nothing for a reader while a mint whose publish failed must
not be left as a token this host holds and no hive can reach.
The token never becomes a nix literal and never reaches argv: the mint
redirects into a file, and the publish hands bao `value=@<path>` so bao
opens it itself — the same handling the OIDC loops use.
`hive-matrix.nix`'s activation mint stays as the genuine first-boot
fallback. It already fires only when the token file is absent, so it
cannot clobber a value the store delivered; `hs_token` has no swarm half
and is still minted there for real.
Refs #4402
199afa41c8