feat: production launch — email audit, team invites, security headers, router fixes

- Fix loyalty & monitoring router bugs (_get_router → named routers)
- Implement team invitation email with send_template + seed templates (en/fr/de)
- Add SecurityHeadersMiddleware (nosniff, HSTS, referrer-policy, permissions-policy)
- Build email audit admin page: service, schemas, API, page route, menu, i18n, HTML, JS
- Clean stale TODO in platform-menu-config.js
- Add 67 tests (unit + integration) covering all new functionality

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/modules/messaging/locales/fr.json

@@ -59,7 +59,52 @@
         "account_settings": "Paramètres du compte",
         "messages": "Messages",
         "notifications": "Notifications",
-        "email_templates": "Modèles d'e-mail"
+        "email_templates": "Modèles d'e-mail",
+        "email_logs": "Journaux d'e-mails"
+    },
+    "email_logs": {
+        "title": "Journaux d'e-mails",
+        "subtitle": "Auditer tous les e-mails envoyés via la plateforme",
+        "recipient": "Destinataire",
+        "subject": "Objet",
+        "template": "Modèle",
+        "status": "Statut",
+        "store": "Boutique",
+        "date": "Date",
+        "sent_at": "Envoyé le",
+        "provider": "Fournisseur",
+        "from": "De",
+        "to": "À",
+        "reply_to": "Répondre à",
+        "related_entity": "Entité liée",
+        "error_message": "Message d'erreur",
+        "actions": "Actions",
+        "view_detail": "Voir le détail",
+        "email_detail": "Détail de l'e-mail",
+        "html_preview": "Aperçu HTML",
+        "text_preview": "Aperçu texte",
+        "metadata": "Métadonnées",
+        "content": "Contenu",
+        "filter_by_recipient": "Rechercher par e-mail du destinataire...",
+        "filter_by_status": "Tous les statuts",
+        "filter_by_template": "Tous les modèles",
+        "filter_by_store": "Toutes les boutiques",
+        "date_from": "Date de début",
+        "date_to": "Date de fin",
+        "apply_filters": "Appliquer",
+        "reset_filters": "Réinitialiser",
+        "total_sent": "Total envoyés",
+        "total_failed": "Échoués",
+        "total_pending": "En attente",
+        "total_delivered": "Livrés",
+        "no_logs": "Aucun journal d'e-mail trouvé",
+        "status_sent": "Envoyé",
+        "status_failed": "Échoué",
+        "status_pending": "En attente",
+        "status_delivered": "Livré",
+        "status_bounced": "Rebondi",
+        "status_opened": "Ouvert",
+        "status_clicked": "Cliqué"
     },
     "permissions": {
         "view_messages": "Voir les messages",