add grafana dashboard

README.md

@@ -58,6 +58,22 @@ Polled usage: `econet_energy_usage_kwh`, `econet_water_usage_gallons`,
 > Note: `econet_wifi_signal_db` is only delivered over Rheem's MQTT push stream,
 > which this exporter does not use — it stays at `0`.
 
+### 📈 Grafana dashboard
+
+The Helm chart ships a ready-made Grafana dashboard
+(`helm/dashboards/econet-exporter.json`). It is **off by default**; enable it by
+setting `hull.config.settings.grafanaDashboard.enabled=true`, which renders a
+ConfigMap labeled `grafana_dashboard: "1"` for the [Grafana sidecar](https://github.com/grafana/helm-charts/tree/main/charts/grafana#sidecar-for-dashboards)
+to auto-import. The dashboard uses the **default Prometheus datasource** (no
+hard-coded UID) and has a multi-select **Device** filter backed by
+`econet_friendly_name`. Tunables under `grafanaDashboard`: `label` / `labelValue`
+(match your sidecar's watch config) and `folder` (target Grafana folder).
+
+```sh
+helm upgrade --install econet ./helm \
+  --set hull.config.settings.grafanaDashboard.enabled=true
+```
+
 ## 📂 Project Structure
 - `proto/econet/v1alpha1/` - Protobuf definitions (source).
 - `api/econet/v1alpha1/` - Generated proto, grpc, grpc-gateway code.