Add missing mysql-data-encrypted PVC definition to bookstack manifests

The MySQL deployment was referencing a PVC that wasn't defined in the
manifests. This PVC exists in the cluster but wasn't tracked by Argo CD.
Adding the definition ensures Argo CD can properly manage all resources
and prevents sync issues.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

apps/bookstack/bookstack-deployment.yaml

@@ -62,6 +62,20 @@ spec:
         persistentVolumeClaim:
           claimName: mysql-data-encrypted
 ---
+# MySQL Data PersistentVolumeClaim
+apiVersion: v1
+kind: PersistentVolumeClaim
+metadata:
+  name: mysql-data-encrypted
+  namespace: bookstack
+spec:
+  accessModes:
+    - ReadWriteOnce
+  storageClassName: hcloud-volumes-encrypted
+  resources:
+    requests:
+      storage: 20Gi
+---
 # MySQL Service
 apiVersion: v1
 kind: Service