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/backup/defaults/main.yml

@@ -0,0 +1,8 @@
+---
+# Role: backup
+# Valeurs par défaut pour les sauvegardes Velero
+
+# Planification des sauvegardes (cron format)
+backup:
+  schedule: "0 2 * * *"
+  retention: "168"  # 7 jours en heures

helms/roles/backup/meta/main.yml

@@ -0,0 +1,11 @@
+---
+galaxy_info:
+  author: Eric FELIXINE
+  description: Deploy Velero backup and disaster recovery solution on Kubernetes
+  license: MIT
+  min_ansible_version: "2.15"
+  platforms:
+    - name: Kubernetes
+      versions:
+        - "1.28"
+dependencies: []

helms/roles/backup/tasks/main.yml

@@ -11,7 +11,7 @@
     values:
       configuration:
         backupStorageLocation:
-          name: default
+          - name: default
             provider: aws
             bucket: smart-city-backup
             config: