Fix Grafana ConfigMap labels lost in configMapGenerator migration

The hand-written configmap.yaml had app.kubernetes.io/name and
app.kubernetes.io/instance labels; configMapGenerator dropped them.
Add options.labels to both generator entries to restore parity.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

argocd/manifests/grafana/kustomization.yaml

@@ -23,6 +23,14 @@ configMapGenerator:
     files:
       - grafana.ini
       - datasources.yaml
+    options:
+      labels:
+        app.kubernetes.io/name: grafana
+        app.kubernetes.io/instance: grafana
   - name: grafana-config-dashboards
     files:
       - provider.yaml
+    options:
+      labels:
+        app.kubernetes.io/name: grafana
+        app.kubernetes.io/instance: grafana