state backup: systemd units (NOT enabled) + cross-host drill script

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

deploy/systemd/windygit-state-backup.service

@@ -0,0 +1,14 @@
+[Unit]
+Description=Windy Git nightly STATE backup (Postgres + Gitea config + repos -> encrypted restic in R2)
+After=network-online.target docker.service
+
+[Service]
+Type=oneshot
+WorkingDirectory=/srv/windygit/src
+# R2 credentials come from the .env; the restic password from /etc/windygit/restic.pass
+# (root 600; the same value lives in the lockbox as RESTIC_WINDYGIT_PASSWORD).
+EnvironmentFile=/srv/windygit/src/.env
+ExecStart=/bin/bash /srv/windygit/src/scripts/backup_state.sh
+Nice=10
+IOSchedulingClass=idle
+TimeoutStartSec=3h

deploy/systemd/windygit-state-backup.service.d/windy-job.conf

@@ -0,0 +1,3 @@
+[Service]
+ExecStart=
+ExecStart=/usr/local/bin/windy-job windygit-state-backup 26h --expect "ok — state backed up" --owner 13 -- /bin/bash /srv/windygit/src/scripts/backup_state.sh

deploy/systemd/windygit-state-backup.timer

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+[Unit]
+Description=Nightly Windy Git state backup
+
+[Timer]
+# 03:07 local, clear of the git-bundle backup at 04:17.
+OnCalendar=*-*-* 03:07:00
+Persistent=true
+RandomizedDelaySec=300
+
+[Install]
+WantedBy=timers.target