nix: ship the journals of the units an apply can leave failed

The units on the path a deploy takes to TLS, the store's grants and the
swarm collector itself were not on the host collector's journald
allowlist, so an ingest outage one of them caused showed in the store
only as every source going quiet at once.

Each module names its own units, per the option's rule:
- hive-tls.nix: hive-tls-ca, swarm-services-cert
- hive-gateway: hive-gateway-self-signed-cert (self-signed mode only)
- swarm-bao.nix: the seven grant units beside
  swarm-bao-services-issuer-policy
- swarm-otel.nix: container@<machine>, and
  nixos-rebuild-switch-to-configuration, the transient unit nixos-rebuild
  runs the activation in and whose syslog lines carry its status

The module-eval arm pins each unit as both listed and defined, since a
listed name that matches nothing is silent.

nix/host-modules/hive-tls.nix

@@ -367,6 +367,13 @@ in
     # rebuild of every hive that is not the CA host, about a fallback
     # that no longer happens.
 
+    # Both run on the deploy and sit on the gateway's start path, so a
+    # failure in either takes TLS down for every service behind it.
+    services.hyperhive.swarm.otel.journaldUnits = [
+      "hive-tls-ca"
+      "swarm-services-cert"
+    ];
+
     # Generate (and rotate) the hive CA + gateway leaf before anything
     # serves it. Idempotent: the CA is created once and reused; the leaf
     # is re-signed on expiry under the same CA so the anchor is stable.