fix(K1): uppercase cluster-vars keys to match component substitution refs

Flux postBuild.substituteFrom is case-sensitive; platform/ components reference
${UPPERCASE} tokens but cluster-vars keys were lowercase -> none would resolve
(literal ${...} would reach the HelmReleases). Uppercased the ConfigMap data
keys + the dev/prod overlay patch paths. Every component ref now resolves;
clusters/dev & clusters/prod build; gate green. Clears the K1 landmine before
any platform un-suspend.

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

clusters/prod/kustomization.yaml

@@ -15,33 +15,33 @@ patches:
       name: cluster-vars
     patch: |-
       - op: replace
-        path: /data/cluster_env
+        path: /data/CLUSTER_ENV
         value: "prod"
       # trusted, rate-limited real certs in prod — ADR-0006.
       - op: replace
-        path: /data/acme_cluster_issuer
+        path: /data/ACME_CLUSTER_ISSUER
         value: "letsencrypt-prod"
       - op: replace
-        path: /data/longhorn_default_replica_count
+        path: /data/LONGHORN_DEFAULT_REPLICA_COUNT
         value: "3"
       # longer retention / larger volumes on prod NVMe.
       - op: replace
-        path: /data/monitoring_prometheus_retention
+        path: /data/MONITORING_PROMETHEUS_RETENTION
         value: "30d"
       - op: replace
-        path: /data/monitoring_prometheus_pvc_size
+        path: /data/MONITORING_PROMETHEUS_PVC_SIZE
         value: "50Gi"
       - op: replace
-        path: /data/monitoring_loki_pvc_size
+        path: /data/MONITORING_LOKI_PVC_SIZE
         value: "50Gi"
       # HA control-plane addons in prod.
       - op: replace
-        path: /data/keycloak_replicas
+        path: /data/KEYCLOAK_REPLICAS
         value: "2"
       - op: replace
-        path: /data/oauth2_proxy_replicas
+        path: /data/OAUTH2_PROXY_REPLICAS
         value: "2"
       - op: replace
-        path: /data/velero_retention
+        path: /data/VELERO_RETENTION
         value: "720h"
       # TODO(WS-INFRA, Phase 7): pin prod node placement once the bare-metal role labels exist.