feat(envs): add staging and prod environments

Clone dev into envs/staging and envs/prod, deploying to namespaces
dbiz-staging and dbiz-prod on the same cluster. App names suffixed per
env, destination namespaces + external-services namespaces + ingress
hosts adjusted. Monitoring kept as a single cluster-wide stack in dev
(not duplicated). Sealed secrets left empty pending per-namespace
re-seal (sealed secrets are namespace-scoped).

envs/prod/apps/sealed-secrets.yaml

@@ -0,0 +1,20 @@
+apiVersion: argoproj.io/v1alpha1
+kind: Application
+metadata:
+  name: dbiz-secrets-prod
+  namespace: argocd
+spec:
+  project: default
+  source:
+    repoURL: https://git.renolation.com/renolation/argo-k8s.git
+    targetRevision: main
+    path: envs/prod/sealed-secrets
+    directory:
+      recurse: true
+  destination:
+    server: https://kubernetes.default.svc
+    namespace: dbiz-prod
+  syncPolicy:
+    automated:
+      prune: true
+      selfHeal: true