Replace plain text input with an API-backed listInput dropdown for
storageClass fields across all applications that expose them.
The dropdown fetches available StorageClasses from the cluster via
/api/clusters/{cluster}/k8s/apis/storage.k8s.io/v1/storageclasses,
following the same pattern as the instanceType dropdown for VMInstance.
Top-level spec.storageClass: ClickHouse, Harbor, HTTPCache, Kubernetes,
MariaDB, MongoDB, NATS, OpenBAO, Postgres, Qdrant, RabbitMQ, Redis, VMDisk.
Nested paths: FoundationDB (spec.storage.storageClass),
Kafka (spec.kafka.storageClass and spec.zookeeper.storageClass).
Co-Authored-By: Claude <noreply@anthropic.com>
Signed-off-by: Kirill Ilin <stitch14@yandex.ru>
c2bf8cf56f