Sync both server snapshots with what the live machines run, and keep their backup tooling

server/home/systemd/media-backup.timer

@@ -0,0 +1,17 @@
+[Unit]
+Description=Weekly Media -> Backup pool copy
+
+[Timer]
+# Saturday 05:00. Clear of: the cron.daily zfs-auto-snapshot window (03:22-03:52),
+# timeshift (04:00), arr-queue-reconcile (04:31), and both ~/Server backups (01:00, 02:00).
+# Saturday specifically because Monday carries the Media scrub and Sunday has
+# raid-check (01:00), docker-prune (05:33) and dind-prune (06:03).
+# gib also runs Nextcloud's borg by hand roughly monthly and is, in his words,
+# not going to be doing that at 5 AM on a Saturday -- so the borg lock should be free.
+OnCalendar=Sat *-*-* 05:00:00
+RandomizedDelaySec=15m
+Persistent=true
+Unit=media-backup.service
+
+[Install]
+WantedBy=timers.target