feat(k8s): add defaults/main.yml, meta/main.yml for all 27 roles + 4 helm templates

- Added defaults/main.yml with production-ready values for all 27 Ansible roles
- Added meta/main.yml with role dependencies (DAG: prereq → namespaces → storage → traefik → cert-manager → services)
- Created 4 missing Helm templates: flink-deployment, kafka-cluster, smartapp-web, smartapp-api
- Fixed YAML syntax error in backup/tasks/main.yml (Velero backupStorageLocation)
- Updated README with domain list, dependencies diagram, and corrected Helm chart names
- All 81 YAML files pass validation

helms/roles/monitoring/defaults/main.yml

@@ -0,0 +1,12 @@
+---
+# Role: monitoring
+# Valeurs par défaut pour Prometheus, Grafana, Loki et Promtail
+
+monitoring:
+  prometheus_retention: "30d"
+  grafana_admin_password: "DUMMY_GRAFANA_ADMIN_PASSWORD"
+
+storage_sizes:
+  prometheus: "50Gi"
+  grafana: "10Gi"
+  loki: "50Gi"