The dashboard's log surface is an allow-list: the four harness units in
every agent container, the hive-ci / hive-forge / hive-matrix machines,
and three host units. `swarm.otel.journaldUnits` only named the host
three plus forgejo — so the units an operator can read in the UI were
absent from the store they are supposed to be queryable in, and nothing
reports that, because a name that matches nothing is not an error.
Adds the four agent units, the CI runner and the homeserver. The agent
units are declared by the hive-c0re module rather than by the
agent-modules that define them: those are a guest evaluation and cannot
reach a host option.
Closes#3818
36082f991f