chore: the systemd unit runs Steward, not FabledNetMon

systemd/fablednetmon.service still carried the project's first name in
its user, paths, command and config location, so it couldn't start
Steward as written. It is now systemd/steward.service: user steward,
/opt/steward, `steward --config /etc/steward/config.yaml`, with a note
that /data must be writable (secret.key, safety backups) and why
Restart=on-failure brings Steward back after a web UI restore (exit 3).

The legacy-name guard now reads service units too, and forbids
"netmon" beside "scryer" and "roundtable". The 2026-04 rebrand plan and
spec under docs/superpowers keep the old names: they record the rename.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

systemd/fablednetmon.service

@@ -1,15 +0,0 @@
-[Unit]
-Description=FabledNetMon monitoring server
-After=network.target postgresql.service
-
-[Service]
-Type=simple
-User=fablednetmon
-WorkingDirectory=/opt/fablednetmon
-ExecStart=/opt/fablednetmon/.venv/bin/fablednetmon --config /etc/fablednetmon/config.yaml
-Restart=on-failure
-RestartSec=5s
-Environment=PYTHONUNBUFFERED=1
-
-[Install]
-WantedBy=multi-user.target

systemd/steward.service

@@ -0,0 +1,21 @@
+# Steward without Docker: the server, run from a virtualenv in /opt/steward.
+# The image is the usual way to run it; this unit is for a host without one.
+# Steward keeps its secret key (secret.key) and its safety backups (backups/)
+# under /data, so the steward user needs to be able to write there.
+[Unit]
+Description=Steward monitoring server
+After=network.target postgresql.service
+
+[Service]
+Type=simple
+User=steward
+WorkingDirectory=/opt/steward
+ExecStart=/opt/steward/.venv/bin/steward --config /etc/steward/config.yaml
+# A restore from the web UI ends with exit code 3, so this brings Steward
+# back with the restored settings (a clean exit 0 would be left stopped).
+Restart=on-failure
+RestartSec=5s
+Environment=PYTHONUNBUFFERED=1
+
+[Install]
+WantedBy=multi-user.target