environment.variables writes to /etc/environment (PAM sessions only)
and is not visible to systemd service units. The correct path for
env vars that need to reach all systemd services is
systemd.globalEnvironment (sets DefaultEnvironment in systemd.conf),
which is the pattern established by #608 for HYPERHIVE_STATE_DIR.
Also update the inline comment reference from environment.variables
to systemd.globalEnvironment.
cce85a6c1b