feat(monitoring): enable Alertmanager (null receiver, longhorn PVC, az-a) + fix forgejo-rules ns forgejo->cicd — alerting delivery was disabled; forgejo PrometheusRule targeted a nonexistent namespace

terraform/templates/worker.tftpl

@@ -71,11 +71,20 @@ machine:
   nodeLabels:
     topology.kubernetes.io/region: homelab
     topology.kubernetes.io/zone: ${zone}
-    node-role.kubernetes.io/gpu-node: ""
 %{ if gpu_count > 0 ~}
+    node-role.kubernetes.io/gpu-node: ""
     nvidia.com/gpu: "true"
     gpu-count: "${gpu_count}"
 %{ endif ~}
+%{ for k, v in node_labels ~}
+    ${k}: "${v}"
+%{ endfor ~}
+%{ if length(node_taints) > 0 ~}
+  nodeTaints:
+%{ for t in node_taints ~}
+    ${t.key}: "${t.value}:${t.effect}"
+%{ endfor ~}
+%{ endif ~}
 
 cluster:
   id: ${cluster_id}