feat(infra): production bootstrap — cert-manager, longhorn, monitoring

Add new bases for cert-manager (Let's Encrypt + wildcard cert), Longhorn
distributed storage, and monitoring (kube-prometheus-stack + Loki + Tempo
+ Grafana OIDC). Add cloud-init for Scaleway Elastic Metal provisioning.

Production overlay: add patches for postgres sizing, SeaweedFS volume,
OpenSearch storage, LiveKit service, Pingora host ports, resource limits,
and CNPG daily barman backups. Update cert-manager.yaml with full dnsNames
for all *.sunbeam.pt subdomains.

overlays/production/patch-seaweedfs-volume-size.yaml

@@ -0,0 +1,15 @@
+# Expand SeaweedFS volume PVC to 600 Gi in production.
+apiVersion: apps/v1
+kind: StatefulSet
+metadata:
+  name: seaweedfs-volume
+  namespace: storage
+spec:
+  volumeClaimTemplates:
+    - metadata:
+        name: data
+      spec:
+        accessModes: [ReadWriteOnce]
+        resources:
+          requests:
+            storage: 600Gi