Initial monorepo scaffold

Turborepo + pnpm monorepo for k3s homelab cluster on Intel NUCs.

- Apps: Next.js web frontend, Express API (TypeScript, Dockerfiles, k8s manifests)
- Packages: shared UI, ESLint config, TypeScript config, Drizzle DB schemas
- Infra/Ansible: bare-metal provisioning with roles for common, k3s-server, k3s-agent, hardening
- Infra/Kubernetes: ArgoCD GitOps (app-of-apps + ApplicationSets), platform components
  (cert-manager, Traefik, CloudNativePG, Valkey, Longhorn, Sealed Secrets), namespaces
- Observability: kube-prometheus-stack, Loki, Promtail as ArgoCD Applications
- CI/CD: GitHub Actions for PR builds, preview deploys, production deploys
- DX: Taskfile, utility scripts, copier templates, Ubiquiti network docs

infra/kubernetes/observability/kube-prometheus-stack/dashboards/cluster-overview.yaml

@@ -0,0 +1,69 @@
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: cluster-overview-dashboard
+  namespace: observability
+  labels:
+    grafana_dashboard: "1"
+data:
+  cluster-overview.json: |
+    {
+      "annotations": { "list": [] },
+      "editable": true,
+      "fiscalYearStartMonth": 0,
+      "graphTooltip": 1,
+      "id": null,
+      "links": [],
+      "panels": [
+        {
+          "title": "CPU Usage by Node",
+          "type": "timeseries",
+          "gridPos": { "h": 8, "w": 12, "x": 0, "y": 0 },
+          "targets": [
+            {
+              "expr": "100 - (avg by(instance) (rate(node_cpu_seconds_total{mode=\"idle\"}[5m])) * 100)",
+              "legendFormat": "{{ instance }}"
+            }
+          ]
+        },
+        {
+          "title": "Memory Usage by Node",
+          "type": "timeseries",
+          "gridPos": { "h": 8, "w": 12, "x": 12, "y": 0 },
+          "targets": [
+            {
+              "expr": "(1 - (node_memory_MemAvailable_bytes / node_memory_MemTotal_bytes)) * 100",
+              "legendFormat": "{{ instance }}"
+            }
+          ]
+        },
+        {
+          "title": "Disk Usage by Node",
+          "type": "timeseries",
+          "gridPos": { "h": 8, "w": 12, "x": 0, "y": 8 },
+          "targets": [
+            {
+              "expr": "(1 - (node_filesystem_avail_bytes{mountpoint=\"/\"} / node_filesystem_size_bytes{mountpoint=\"/\"})) * 100",
+              "legendFormat": "{{ instance }}"
+            }
+          ]
+        },
+        {
+          "title": "Pod Count by Namespace",
+          "type": "bargauge",
+          "gridPos": { "h": 8, "w": 12, "x": 12, "y": 8 },
+          "targets": [
+            {
+              "expr": "count by(namespace) (kube_pod_info)",
+              "legendFormat": "{{ namespace }}"
+            }
+          ]
+        }
+      ],
+      "schemaVersion": 39,
+      "tags": ["homelab", "cluster"],
+      "templating": { "list": [] },
+      "time": { "from": "now-6h", "to": "now" },
+      "title": "Cluster Overview",
+      "uid": "cluster-overview"
+    }