Add cron schedules and sync docs

deploy/grafana/README.md

@@ -1,11 +1,20 @@
 # Grafana
 
-Placeholder for Grafana dashboard examples.
+Starter Grafana provisioning for the optional observability profile.
 
-Planned dashboards:
+Files:
 
-- agents alive/stale/dead;
-- check state counts;
-- open incidents;
-- notification outbox state;
-- server ingestion and notifier failures.
+- `provisioning/datasources/prometheus.yml` - adds Prometheus at `http://prometheus:9090`.
+- `provisioning/dashboards/monlet.yml` - loads dashboards from `/var/lib/grafana/dashboards`.
+- `dashboards/monlet-overview.json` - starter dashboard for agent status, open incidents, event ingest rate, and notification rate.
+
+Run it with:
+
+```sh
+cd deploy
+MONLET_AUTH_TOKEN=$(openssl rand -hex 16) docker compose --profile observability up
+```
+
+Grafana is exposed at <http://127.0.0.1:3001>. The local default is
+`admin` / `admin` unless `GF_ADMIN_PASSWORD` is set. Change it before exposing
+Grafana outside local development.