fix: remover hardcoded ARM64 de aula-08/13/14 para suportar amd64

- aula-08/outputs.tf: usar local.selected_arch ao invés de CAX11 fixo
- aula-08/cleanup.sh: detectar arch dos nodes para filtrar instance type
- aula-08/setup.sh: custos estimados baseados na arch selecionada
- aula-13/prepare-images.sh: detectar arch do cluster automaticamente
- aula-14/setup.sh: detectar arch do cluster para build correto

aula-08/outputs.tf

@@ -116,8 +116,8 @@ output "connection_instructions" {
        https://${local.cluster_endpoint_ip}:6443
 
     4. Nodes:
-       Control Plane: ${local.control_plane_count}x CAX11 (ARM64)
-       Workers: 1x CAX11 (ARM64)
+       Control Plane: ${local.control_plane_count}x ${local.selected_arch.server_type_cp} (${var.arch})
+       Workers: 1x ${local.selected_arch.server_type_cp} (${var.arch})
        ${var.enable_loadbalancer ? "Load Balancer: LB11" : "Floating IP: IPv4"}
 
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