T-0.1 Flux GitOps layout + dev/prod overlays + platform component skeletons (R-GITOPS-01/03, R-ENV-02, R-PLAT-01)

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>

clusters/dev/kustomization.yaml

@@ -0,0 +1,46 @@
+---
+# clusters/dev — the ACTIVE build target overlay.
+#
+# `flux bootstrap ... --path=clusters/dev` points the dev cluster's Flux here.
+# This overlay adds NO resources of its own. Its ONLY job is to patch the shared cluster-vars
+# ConfigMap with dev-scoped values (R-ENV-02). The base reconciliation graph is reused verbatim.
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: Kustomization
+resources:
+  - ../base
+patches:
+  - target:
+      kind: ConfigMap
+      name: cluster-vars
+    patch: |-
+      - op: replace
+        path: /data/cluster_env
+        value: "dev"
+      # DNS-01 against LE staging while iterating (avoids prod rate limits) — ADR-0006.
+      - op: replace
+        path: /data/acme_cluster_issuer
+        value: "letsencrypt-staging"
+      # dev mirrors prod's 3-node topology, so the replicated tier keeps 3 replicas.
+      - op: replace
+        path: /data/longhorn_default_replica_count
+        value: "3"
+      # smaller retention / volumes to keep the dev workstation footprint light.
+      - op: replace
+        path: /data/monitoring_prometheus_retention
+        value: "3d"
+      - op: replace
+        path: /data/monitoring_prometheus_pvc_size
+        value: "5Gi"
+      - op: replace
+        path: /data/monitoring_loki_pvc_size
+        value: "5Gi"
+      # single-replica control-plane addons in dev (no HA needed to iterate).
+      - op: replace
+        path: /data/keycloak_replicas
+        value: "1"
+      - op: replace
+        path: /data/oauth2_proxy_replicas
+        value: "1"
+      - op: replace
+        path: /data/velero_retention
+        value: "72h"