feat(clickhouse): enable Prometheus monitoring

clickhouse/README.md

@@ -44,3 +44,31 @@ ClickHouse can use the following Linux capabilities for enhanced performance, bu
 | `SYS_NICE` | Thread priority control via `os_thread_priority` | Setting has no effect                         |
 
 These capabilities are disabled by default to comply with baseline Pod Security Standards. To enable them, the namespace must allow privileged pods, and you need to uncomment the `add` line in `clickhouse-installation-template.yaml`.
+
+## Monitoring
+
+ClickHouse exposes Prometheus metrics on port 9363. When Prometheus (kube-prometheus-stack) is installed, monitoring can be enabled during installation or manually.
+
+### Enable Monitoring
+
+```bash
+just clickhouse::setup-monitoring
+```
+
+This creates a ServiceMonitor and a metrics Service for Prometheus to scrape.
+
+### Grafana Dashboard
+
+Import the ClickHouse dashboard from Grafana.com:
+
+1. Open Grafana → **Dashboards** → **New** → **Import**
+2. Enter Dashboard ID: `14192`
+3. Click **Load**, select **Prometheus** data source, then **Import**
+
+The dashboard includes panels for memory, connections, queries, I/O, replication, merge operations, cache, and ZooKeeper metrics.
+
+### Remove Monitoring
+
+```bash
+just clickhouse::remove-monitoring
+```