Second slice of the swarm-global service consolidation, same shape as
the forge move: the operator-facing host options become
services.hyperhive.swarm.matrix.*, and one mkRenamedOptionModule on the
namespace carries the whole subtree (nested gui.* included), so there is
no leaf list to forget an entry from.
The rename lives in hive-matrix.nix, the module that declares the
options, so each service's migration stays independent of its siblings.
The per-agent hyperhive.matrix.{enable,url} and hyperhive.matrixAccounts
are a different namespace -- a client pointer at the service, not the
service -- and deliberately do not move.
fcdff04b23