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/httproute_operator-test.yaml

@@ -0,0 +1,24 @@
+---
+apiVersion: gateway.networking.k8s.io/v1
+kind: HTTPRoute
+metadata:
+  name: operator-test
+  namespace: default
+  labels:
+    app: operator-test
+spec:
+  parentRefs:
+    - name: cilium-gateway
+      namespace: kube-system
+      sectionName: auto-operator-test-lab-home-hrajfrisbee-operator-test-lab-home-hrajfrisbee-cz
+  hostnames:
+    - operator-test.lab.home.hrajfrisbee.cz
+  rules:
+    - matches:
+        - path:
+            type: PathPrefix
+            value: /
+      backendRefs:
+        - name: operator-test
+          namespace: default
+          port: 80