The operator asked for this when the dashboard was first reviewed and it was
deferred, not declined: the container metric family carried no hive label, so
selecting a hive emptied every container panel while the "All" default hid the
problem completely -- a `.*` matcher matches series where the label is absent.
That family now carries hive and swarm, verified against the live store rather
than inferred from the fix having merged: a hive selection returns the same 7
agents as the All default, at every window out to 168h, with a nonexistent
hive returning zero.
The agent list chains off the hive selection, so picking a hive narrows the
agent dropdown rather than leaving entries in it that resolve to nothing.