vault: implement bootstrap integration

terraform/vms.tf

@@ -66,6 +66,8 @@ locals {
       gateway = lookup(vm, "gateway", var.default_gateway)
       # Branch configuration for bootstrap (optional, uses master if not set)
       flake_branch = lookup(vm, "flake_branch", null)
+      # Vault configuration (optional, for automatic secret provisioning)
+      vault_wrapped_token = lookup(vm, "vault_wrapped_token", null)
     }
   }
 }