fix(i18n): add missing menu translations and fix admin language resolution

Two issues caused the admin sidebar to show a mix of French and English:

1. Only 3 of 14 modules had "menu" translations in their locale files.
   When a key was missing, _translate_label() fell back to English Title
   Case from the key name — mixing with French from modules that had
   translations. Added menu sections to all 4 languages (en, fr, de, lb)
   across 13 modules.

2. The language middleware hardcoded admin to "en" ignoring user preference,
   while the menu API fell back to DEFAULT_LANGUAGE ("fr") when
   preferred_language was NULL. Fixed middleware to respect user's
   preferred_language and menu API to use middleware-resolved language
   as fallback.

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

app/modules/orders/locales/fr.json

@@ -1,78 +1,83 @@
 {
-  "orders": {
-    "title": "Commandes",
-    "order": "Commande",
-    "order_id": "ID de commande",
-    "order_number": "Numéro de commande",
-    "order_date": "Date de commande",
-    "order_status": "Statut de la commande",
-    "order_details": "Détails de la commande",
-    "order_items": "Articles de la commande",
-    "order_total": "Total de la commande",
-    "subtotal": "Sous-total",
-    "shipping": "Livraison",
-    "tax": "Taxe",
-    "discount": "Remise",
-    "customer": "Client",
-    "shipping_address": "Adresse de livraison",
-    "billing_address": "Adresse de facturation",
-    "payment_method": "Mode de paiement",
-    "payment_status": "Statut du paiement",
-    "tracking": "Suivi",
-    "tracking_number": "Numéro de suivi",
-    "carrier": "Transporteur",
-    "no_orders": "Aucune commande trouvée",
-    "search_orders": "Rechercher des commandes...",
-    "filter_by_status": "Filtrer par statut",
-    "status_pending": "En attente",
-    "status_processing": "En cours",
-    "status_shipped": "Expédiée",
-    "status_delivered": "Livrée",
-    "status_cancelled": "Annulée",
-    "status_refunded": "Remboursée",
-    "status_confirmed": "Confirmée",
-    "status_rejected": "Rejetée",
-    "confirm_order": "Confirmer la commande",
-    "reject_order": "Rejeter la commande",
-    "set_tracking": "Définir le suivi",
-    "view_details": "Voir les détails"
-  },
-  "messages": {
-    "order_status_updated": "Order status updated",
-    "item_shipped_successfully": "Item shipped successfully",
-    "all_items_shipped": "All items shipped",
-    "invoice_downloaded": "Invoice downloaded",
-    "failed_to_load_order_details": "Failed to load order details.",
-    "order_status_updated_successfully": "Order status updated successfully.",
-    "order_marked_as_shipped_successfully": "Order marked as shipped successfully.",
-    "no_shipping_label_url_available_for_this": "No shipping label URL available for this order."
-  },
-  "features": {
-    "orders_per_month": {
-      "name": "Commandes mensuelles",
-      "description": "Nombre maximum de commandes par mois",
-      "unit": "commandes/mois"
+    "orders": {
+        "title": "Commandes",
+        "order": "Commande",
+        "order_id": "ID de commande",
+        "order_number": "Numéro de commande",
+        "order_date": "Date de commande",
+        "order_status": "Statut de la commande",
+        "order_details": "Détails de la commande",
+        "order_items": "Articles de la commande",
+        "order_total": "Total de la commande",
+        "subtotal": "Sous-total",
+        "shipping": "Livraison",
+        "tax": "Taxe",
+        "discount": "Remise",
+        "customer": "Client",
+        "shipping_address": "Adresse de livraison",
+        "billing_address": "Adresse de facturation",
+        "payment_method": "Mode de paiement",
+        "payment_status": "Statut du paiement",
+        "tracking": "Suivi",
+        "tracking_number": "Numéro de suivi",
+        "carrier": "Transporteur",
+        "no_orders": "Aucune commande trouvée",
+        "search_orders": "Rechercher des commandes...",
+        "filter_by_status": "Filtrer par statut",
+        "status_pending": "En attente",
+        "status_processing": "En cours",
+        "status_shipped": "Expédiée",
+        "status_delivered": "Livrée",
+        "status_cancelled": "Annulée",
+        "status_refunded": "Remboursée",
+        "status_confirmed": "Confirmée",
+        "status_rejected": "Rejetée",
+        "confirm_order": "Confirmer la commande",
+        "reject_order": "Rejeter la commande",
+        "set_tracking": "Définir le suivi",
+        "view_details": "Voir les détails"
     },
-    "order_history_months": {
-      "name": "Historique des commandes",
-      "description": "Mois d'historique des commandes conservés",
-      "unit": "mois"
+    "messages": {
+        "order_status_updated": "Order status updated",
+        "item_shipped_successfully": "Item shipped successfully",
+        "all_items_shipped": "All items shipped",
+        "invoice_downloaded": "Invoice downloaded",
+        "failed_to_load_order_details": "Failed to load order details.",
+        "order_status_updated_successfully": "Order status updated successfully.",
+        "order_marked_as_shipped_successfully": "Order marked as shipped successfully.",
+        "no_shipping_label_url_available_for_this": "No shipping label URL available for this order."
     },
-    "order_management": {
-      "name": "Gestion des commandes",
-      "description": "Fonctionnalités complètes de gestion des commandes"
+    "features": {
+        "orders_per_month": {
+            "name": "Commandes mensuelles",
+            "description": "Nombre maximum de commandes par mois",
+            "unit": "commandes/mois"
+        },
+        "order_history_months": {
+            "name": "Historique des commandes",
+            "description": "Mois d'historique des commandes conservés",
+            "unit": "mois"
+        },
+        "order_management": {
+            "name": "Gestion des commandes",
+            "description": "Fonctionnalités complètes de gestion des commandes"
+        },
+        "order_bulk_actions": {
+            "name": "Actions en masse",
+            "description": "Effectuer des actions en masse sur les commandes"
+        },
+        "order_export": {
+            "name": "Export de commandes",
+            "description": "Exporter les données de commandes"
+        },
+        "automation_rules": {
+            "name": "Règles d'automatisation",
+            "description": "Règles de traitement automatique des commandes"
+        }
     },
-    "order_bulk_actions": {
-      "name": "Actions en masse",
-      "description": "Effectuer des actions en masse sur les commandes"
-    },
-    "order_export": {
-      "name": "Export de commandes",
-      "description": "Exporter les données de commandes"
-    },
-    "automation_rules": {
-      "name": "Règles d'automatisation",
-      "description": "Règles de traitement automatique des commandes"
+    "menu": {
+        "store_operations": "Opérations du magasin",
+        "sales_orders": "Ventes et Commandes",
+        "orders": "Commandes"
     }
-  }
 }