tofu config and docs

.tofu/platforms/upc/modules/cluster/main.tf

@@ -47,6 +47,14 @@ resource "upcloud_kubernetes_node_group" "workers" {
   node_count    = var.node_count
   plan          = var.node_plan
   anti_affinity = var.node_count > 1
+
+  dynamic "cloud_native_plan" {
+    for_each = var.storage_size != null ? [1] : []
+    content {
+      storage_size = var.storage_size
+    }
+  }
+
   labels = {
     prefix  = var.prefix
     cluster = var.cluster_name

.tofu/platforms/upc/modules/cluster/variables.tf

@@ -38,6 +38,12 @@ variable "control_plane_ip_filter" {
   default     = ["0.0.0.0/0"]
 }
 
+variable "storage_size" {
+  description = "Storage size in GB for worker nodes (overrides plan default via cloud_native_plan block)"
+  type        = number
+  default     = null
+}
+
 variable "tags" {
   description = "Labels to apply to resources"
   type        = map(string)