Add reusable storage pool module with lvmcluster san pool

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

incus/variables.tf

@@ -15,3 +15,11 @@ variable "incus_token" {
 variable "incus_networks" {
   type = map(number)
 }
+
+variable "incus_storage_pools" {
+  type = map(object({
+    driver            = string
+    hypervisor_config = map(string)
+    witness_config    = map(string)
+  }))
+}