Add deploy script, backup script and crontab for the server

- deploy/uiogaming-deploy: forced command for github_deploy's SSH key. Pulls the repo and rebuilds one service from /srv/uiogaming/docker-compose.yml, fixing deploys that failed on container-name conflicts.
- backup/backup_db.sh: nightly pg_dumpall of all databases, gzipped, 14-day retention.
- cron/uiogaming.crontab: the uiogaming user's crontab.
- Document the new deploy setup and the move to /srv/uiogaming.

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

backup/backup_db.sh

@@ -0,0 +1,24 @@
+#!/bin/bash
+# Nightly dump of all Postgres databases + roles, compressed.
+# Installed on the server as /srv/uiogaming/.backups/backup_db.sh, run by cron (see ../cron/uiogaming.crontab).
+# The rsync user pulls the backup folder to off-site storage every night at 03:00.
+#
+# Restore: gunzip -c backup_YYYY-MM-DD.sql.gz | docker exec -i postgres psql -U postgres
+set -euo pipefail
+
+BACKUP_DIR=/srv/uiogaming/.backups/postgres
+KEEP_DAYS=14
+
+log()  { echo "$(date '+%Y-%m-%d %H:%M:%S') $*"; }
+fail() { log "Backup FAILED: $*" >&2; rm -f "$BACKUP_FILE"; exit 1; }
+
+mkdir -p "$BACKUP_DIR"
+BACKUP_FILE="$BACKUP_DIR/backup_$(date +%F).sql.gz"
+trap 'fail "error on line $LINENO"' ERR
+
+log "Backing up all databases"
+docker exec postgres pg_dumpall -U postgres | gzip > "$BACKUP_FILE"
+[[ $(gunzip -c "$BACKUP_FILE" | tail -n 5) == *"cluster dump complete"* ]] || fail "dump incomplete"
+log "Backup completed: $BACKUP_FILE ($(du -h "$BACKUP_FILE" | cut -f1))"
+
+find "$BACKUP_DIR" -name 'backup_*.sql*' -mtime +"$KEEP_DAYS" -delete