Litestream replication to the NAS and nightly media backup

Add a litestream service (0.5.17) to the compose stack that streams
/data/mealquest.db over SFTP to the Synology NAS with a dedicated key,
daily snapshots kept for a week. Add a systemd timer that rsyncs the
media directory to the NAS nightly at 03:30.

Task: d2f2e87e-5114-4ef1-93ab-360ffb5c009e

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

deploy/systemd/mealquest-media-backup.service

@@ -0,0 +1,13 @@
+# Runs the nightly MealQuest media backup (/usr/local/sbin/mealquest-media-backup).
+# Triggered by mealquest-media-backup.timer; run by hand with
+#   systemctl start mealquest-media-backup
+# and read the result with
+#   journalctl -u mealquest-media-backup
+[Unit]
+Description=Back up MealQuest media to the Synology NAS
+After=network-online.target
+Wants=network-online.target
+
+[Service]
+Type=oneshot
+ExecStart=/usr/local/sbin/mealquest-media-backup

deploy/systemd/mealquest-media-backup.sh

@@ -0,0 +1,40 @@
+#!/bin/sh
+# Nightly copy of the MealQuest media directory (recipe and dinner photos)
+# to the Synology NAS. The database itself is replicated continuously by
+# Litestream; this covers the files beside it.
+#
+# rsync mirrors the media directory onto .../mealquest-backups/media/ only:
+# both paths end in a slash, so --delete removes files from that target
+# directory and nothing outside it. A missing source directory (no media
+# uploaded yet) is reported and skipped, never synced, so an empty source
+# can never wipe the remote copy. Re-runs transfer only what changed.
+#
+# The volume is writable by the app container, so a media path that is a
+# symlink is refused: root's rsync would otherwise follow it and copy
+# whatever it points at. Symlinks inside the directory are copied as links
+# (-a), never followed.
+#
+# Connects with the dedicated MealQuest key; the NAS host key must already
+# be in root's known_hosts (StrictHostKeyChecking=yes fails otherwise).
+# Installed as /usr/local/sbin/mealquest-media-backup; output goes to the
+# journal via mealquest-media-backup.service.
+set -eu
+
+src=/var/lib/docker/volumes/mealquest-data/_data/media/
+dest=joshua@10.60.1.50:/volume1/homes/Joshua/mealquest-backups/media/
+key=/home/overseer/mealquest/deploy/secrets/litestream_key
+
+if [ -L "${src%/}" ]; then
+	echo "mealquest-media-backup: ${src%/} is a symlink; refusing to back it up" >&2
+	exit 1
+fi
+
+if [ ! -d "$src" ]; then
+	echo "mealquest-media-backup: no media directory at $src yet; nothing to back up"
+	exit 0
+fi
+
+rsync -a --delete --stats \
+	-e "ssh -i $key -o IdentitiesOnly=yes -o BatchMode=yes -o StrictHostKeyChecking=yes" \
+	"$src" "$dest"
+echo "mealquest-media-backup: synced $src to $dest"

deploy/systemd/mealquest-media-backup.timer

@@ -0,0 +1,11 @@
+# Nightly trigger for mealquest-media-backup.service. Persistent= runs a
+# missed backup at the next boot.
+[Unit]
+Description=Nightly MealQuest media backup
+
+[Timer]
+OnCalendar=*-*-* 03:30:00
+Persistent=true
+
+[Install]
+WantedBy=timers.target