feat(observability): OneLab-only Promtail, provisioned OneLab logs dashboard

- Promtail: keep kubernetes-pods in namespace onelab; tag host file logs (host-logs)
- Grafana: enable dashboard sidecar; ConfigMap onelab-logs.json
- Dashboard: stats (total/error/warn heuristics), logs panel, component + regex filters

Made-with: Cursor

gitops/observability/templates/configmap-dashboard-onelab-logs.yaml

@@ -0,0 +1,14 @@
+{{- if .Values.grafana.sidecar.dashboards.enabled }}
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: {{ printf "%s-dashboard-onelab-logs" .Release.Name | trunc 63 | trimSuffix "-" }}
+  namespace: {{ .Release.Namespace }}
+  labels:
+    grafana_dashboard: "1"
+  annotations:
+    argocd.argoproj.io/sync-wave: "0"
+data:
+  onelab-logs.json: |-
+{{ .Files.Get "dashboards/onelab-logs.json" | nindent 4 }}
+{{- end }}