Add standalone backup script and admin update-check banner

ops/backup.sh snapshots LDAP (slapcat), Redis (BGSAVE, dynamic RDB path
lookup), and ./config for standalone deployments, with retention. A
background service polls GitHub releases every 24h and surfaces an
admin-only banner in the UI when a newer version is published.

Dockerfile.openldap

@@ -84,6 +84,7 @@ COPY nodejs/controller ./controller
 COPY nodejs/middleware ./middleware
 COPY nodejs/models ./models
 COPY nodejs/routes ./routes
+COPY nodejs/services ./services
 COPY nodejs/utils ./utils
 COPY nodejs/views ./views
 COPY nodejs/public ./public