feat: Move cluster services to wild-directory as unified packages

Convert all 15 cluster services from embedded API format to
wild-directory packages using the unified manifest format:
- metallb, traefik, cert-manager, longhorn, snapshot-controller
- nfs, smtp, coredns, node-feature-discovery, nvidia-device-plugin
- externaldns, docker-registry, headlamp, crowdsec, utils

Changes:
- wild-manifest.yaml → manifest.yaml with is, defaultConfig, requires
- Eliminated configReferences and serviceConfig fields
- Flattened kustomize.template/ to package root
- Template vars use flat defaultConfig keys
- install.sh paths updated for apps/ layout
- Updated 9 app manifests: cloud.smtp.* → apps.smtp.* with requires
- Removed dead install: true field from 6 app manifests

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

node-feature-discovery/rbac.yaml

@@ -0,0 +1,55 @@
+apiVersion: v1
+kind: ServiceAccount
+metadata:
+  name: node-feature-discovery
+  namespace: node-feature-discovery
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRole
+metadata:
+  name: node-feature-discovery
+rules:
+- apiGroups:
+  - ""
+  resources:
+  - nodes
+  - nodes/status
+  verbs:
+  - get
+  - patch
+  - update
+  - list
+- apiGroups:
+  - ""
+  resources:
+  - namespaces
+  verbs:
+  - get
+  - list
+  - watch
+- apiGroups:
+  - nfd.k8s-sigs.io
+  resources:
+  - nodefeatures
+  - nodefeaturerules
+  - nodefeaturegroups
+  verbs:
+  - get
+  - list
+  - watch
+  - create
+  - update
+  - patch
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRoleBinding
+metadata:
+  name: node-feature-discovery
+roleRef:
+  apiGroup: rbac.authorization.k8s.io
+  kind: ClusterRole
+  name: node-feature-discovery
+subjects:
+- kind: ServiceAccount
+  name: node-feature-discovery
+  namespace: node-feature-discovery