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/certificate_operator-test-2.yaml

@@ -0,0 +1,17 @@
+apiVersion: cert-manager.io/v1
+kind: Certificate
+metadata:
+  name: operator-test-lab-home-hrajfrisbee-2
+  namespace: default
+  annotations:
+    gateway-cert-operator.io/gateway-name: "cilium-gateway"
+    gateway-cert-operator.io/gateway-namespace: "kube-system"
+
+spec:
+  secretName: operator-test-lab-home-hrajfrisbee-2
+  issuerRef:
+    group: cert-manager.io
+    kind: ClusterIssuer
+    name: letsencrypt-prod
+  dnsNames:
+    - "operator-test-2.lab.home.hrajfrisbee.cz"