REFACTOR(repo): platform repo structure

- Add application.yaml for ArgoCD app-of-apps
- Add kustomization.yaml with platform components
- Add renovate.json for automated updates
- Update cert-manager/argocd.yaml repoURL to platform repo
- Update traefik/argocd.yaml repoURL to platform repo

cert-manager/argocd.yaml

@@ -14,10 +14,10 @@ spec:
     helm:
       valueFiles:
       - $values/cert-manager/helm-values.yaml
-  - repoURL: https://github.com/K3S-HOME/cluster-infrastructure.git
+  - repoURL: https://github.com/K3S-HOME/platform.git
     targetRevision: main
     ref: values
-  - repoURL: https://github.com/K3S-HOME/cluster-infrastructure.git
+  - repoURL: https://github.com/K3S-HOME/platform.git
     targetRevision: main
     path: cert-manager
   destination: