fix: remove PVC patch that broke kubectl apply on bound claims

The mysql-data-pvc was already dynamically provisioned by the cluster's
'local-path' StorageClass. The overlay patch tried to change storageClassName
to 'manual' and volumeName on an already-bound PVC, which Kubernetes forbids:
  "spec is immutable after creation except resources.requests"

Fixes:
- Remove mysql-pvc-patch from kustomization.yaml (PVC left as-is)
- Remove mysql-pv.yaml resource (not needed with dynamic provisioner)
- Add comment explaining when manual PV/PVC is needed vs not

Jenkinsfile: add --timeout and FQDN to smoke test curl; add comments
explaining MySQL Recreate strategy startup timing expectations.

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

k8s/overlays/on-premise/kustomization.yaml

@@ -19,11 +19,10 @@ resources:
   - ../../base
   - ingress.yaml
 
-patches:
-  - path: mysql-pvc-patch.yaml
-    target:
-      kind: PersistentVolumeClaim
-      name: mysql-data-pvc
+# NOTE: mysql-pv.yaml and mysql-pvc-patch.yaml are only needed on clusters
+# without a default StorageClass. This cluster uses 'local-path' (dynamic
+# provisioner), so the base PVC works as-is and must NOT be patched after
+# it is already bound.
 
 images:
   - name: scrum-frontend