gitops: upgrade Cilium to 1.19.1, add fujarna app, flux web UI, OIDC RBAC, and experiments

- Upgrade Cilium helm release from 1.18.5 to 1.19.1 with gatewayClass creation enabled
- Escalate gitea CI service account to cluster-admin, add OIDC cluster-admin binding
- Deploy fujarna app with full manifest set (deployment, service, PVC, httproutes, external secret)
- Add Flux web UI via flux-operator OCI repository and helm release
- Add experiments kustomization with test resources for gateway API and certificates

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

gitops/home-kubernetes/experiments/service_operator-test.yaml

@@ -0,0 +1,15 @@
+---
+apiVersion: v1
+kind: Service
+metadata:
+  name: operator-test
+  namespace: default
+spec:
+  type: ClusterIP
+  selector:
+    app: operator-test
+  ports:
+    - port: 80
+      targetPort: 80
+      protocol: TCP
+      name: http