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>

nfs/README.md

@@ -0,0 +1,60 @@
+# NFS Setup (Optional)
+
+The infrastructure supports optional NFS (Network File System) for shared media storage across the cluster. If your config.yaml contains the `cloud.nfs` section, the NFS server will be set up automatically.
+
+## Host Setup
+
+First, set up the NFS server on your chosen host.
+
+```bash
+./setup-nfs-host.sh <host> <media-path>
+```
+
+Example:
+
+```bash
+./setup-nfs-host.sh box-01 /srv/nfs
+```
+
+## Cluster Integration
+
+Add to your `config.yaml`:
+
+```yaml
+cloud:
+  nfs:
+    host: box-01
+    mediaPath: /srv/nfs
+    storageCapacity: 250Gi # Max size for PersistentVolume
+```
+
+And now you can run the nfs cluster setup:
+
+```bash
+setup/setup-nfs-host.sh
+```
+
+## Features
+
+- Automatic IP detection - Uses network IP even when hostname resolves to localhost
+- Cluster-wide access - Any pod can mount the NFS share regardless of node placement
+- Configurable capacity - Set PersistentVolume size via `NFS_STORAGE_CAPACITY`
+- ReadWriteMany - Multiple pods can simultaneously access the same storage
+
+## Usage
+
+Applications can use NFS storage by setting `storageClassName: nfs` in their PVCs:
+
+```yaml
+apiVersion: v1
+kind: PersistentVolumeClaim
+metadata:
+  name: media-pvc
+spec:
+  accessModes:
+    - ReadWriteMany
+  storageClassName: nfs
+  resources:
+    requests:
+      storage: 100Gi
+```