Fix degraded ArgoCD applications

- frigate: Remove duplicate PVCs (Helm manages them), update config size to 15Gi
- gitlab: Fix sync-admin-job secretKeyRef schema error, fetch password via kubectl
- nextcloud: Remove duplicate PVC, remove invalid pod-level securityContext
- rook-ceph: Update cephfs-smb-pvc to 50Gi, remove unsupported dashboard.config
- nessus: Add privileged PSS label for NET_ADMIN/NET_RAW capabilities
- scylla-manager: Add privileged PSS label for SYS_NICE capability
- n8n: Create missing n8n-main-persistence PVC
- projects: Add authentik namespace to applications project destinations

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

apps/n8n/manifests/pvc.yaml

@@ -0,0 +1,14 @@
+apiVersion: v1
+kind: PersistentVolumeClaim
+metadata:
+  name: n8n-main-persistence
+  namespace: n8n
+  labels:
+    app.kubernetes.io/name: n8n
+spec:
+  accessModes:
+    - ReadWriteOnce
+  storageClassName: rook-ceph-block
+  resources:
+    requests:
+      storage: 10Gi