`clientCn` fell back to `cfg.domain` when `hiveName` was unset. That branch
cannot run: `hive-network.nix` asserts `hiveName != null` under
`mkIf services.hyperhive.enable`, and this file's `config` is gated on the same
predicate, so any host that evaluates the conditional has already failed the
assertion.
Worse than dead, it read as a second supported spelling of a hive's identity —
which is what a cert-auth role matches on. It was not even the hive's own
domain: `cfg` here is `services.hyperhive.swarm.bao`, so the fallback resolved
to the store's address, one string shared by every hive in the swarm and the
same CN the server leaf carries.
Reading the option directly matches what other modules needing the name already
do (`hive-c0re/environment.nix`).