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]>

platform/gateway/gatewayclass.yaml

@@ -0,0 +1,9 @@
+---
+# GatewayClass implemented by Cilium (ADR-0002: Gateway API via Cilium, no separate ingress
+# controller). Phase 0 STUB. The controllerName is provided by the Cilium Gateway API integration.
+apiVersion: gateway.networking.k8s.io/v1
+kind: GatewayClass
+metadata:
+  name: cilium
+spec:
+  controllerName: io.cilium/gateway-controller