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>

docker-registry/deployment.yaml

@@ -0,0 +1,48 @@
+---
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: docker-registry
+  labels:
+    app: docker-registry
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: docker-registry
+  strategy:
+    rollingUpdate:
+      maxSurge: 0
+      maxUnavailable: 1
+    type: RollingUpdate
+  template:
+    metadata:
+      labels:
+        app: docker-registry
+    spec:
+      securityContext:
+        runAsNonRoot: true
+        runAsUser: 1000
+        runAsGroup: 1000
+        fsGroup: 1000
+        seccompProfile:
+          type: RuntimeDefault
+      containers:
+        - image: registry:3.0.0
+          name: docker-registry
+          securityContext:
+            allowPrivilegeEscalation: false
+            capabilities:
+              drop:
+                - ALL
+          ports:
+            - containerPort: 5000
+              protocol: TCP
+          volumeMounts:
+            - mountPath: /var/lib/registry
+              name: docker-registry-storage
+              readOnly: false
+      volumes:
+        - name: docker-registry-storage
+          persistentVolumeClaim:
+            claimName: docker-registry-pvc