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-13/benchmarks/prepare-images.sh

@@ -21,7 +21,9 @@ set -euo pipefail
 
 REGISTRY="${REGISTRY:-gitea.kube.quest}"
 ORG="bench"
-PLATFORM="linux/arm64"  # Hetzner CAX = ARM64
+# Detectar arquitetura do cluster automaticamente
+NODE_ARCH=$(kubectl get nodes -o jsonpath='{.items[0].metadata.labels.kubernetes\.io/arch}' 2>/dev/null || echo "arm64")
+PLATFORM="linux/${NODE_ARCH}"
 
 RED='\033[0;31m'
 GREEN='\033[0;32m'