fix: update dashboards and OTel collector for proper metrics/logs

- certmanager.json: use Thanos datasource, fix variable regex
- argocd.json: use Thanos datasource via $datasource variable
- logs.json: update to use OTel labels (k8s_namespace_name, k8s_container_name)
- collector.yaml: add loki.resource.labels hint for proper Loki label mapping

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

opentelemetry-collector/manifests/collector.yaml

@@ -142,6 +142,13 @@ spec:
           - type: move
             from: attributes.log
             to: body
+          # Loki label hints - tell Loki exporter which attributes to use as labels
+          - type: add
+            field: resource["loki.resource.labels"]
+            value: "k8s.namespace.name, k8s.pod.name, k8s.container.name, k8s.node.name"
+          - type: add
+            field: attributes["loki.attribute.labels"]
+            value: "log.iostream"
 
       # Prometheus receiver - self metrics only
       prometheus:
@@ -202,7 +209,7 @@ spec:
       loki:
         endpoint: http://loki.loki.svc.cluster.local:3100/loki/api/v1/push
         default_labels_enabled:
-          exporter: true
+          exporter: false
           level: true
 
       debug: