refactor: rename 'Livebox / Box FAI' to 'Passerelle Internet' in device form

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

frontend/src/i18n.js

@@ -53,7 +53,7 @@ const LANGS = {
     fieldType: 'Type *',
     fieldDescription: 'Description',
     isGateway: 'Passerelle inter-VLAN',
-    isLivebox: 'Livebox / Box FAI',
+    isLivebox: 'Passerelle Internet',
     accessUrl: "URL d'accès",
     runtimeType: "Type d'environnement d'exécution",
     notSpecified: '— Non précisé',
@@ -215,7 +215,7 @@ const LANGS = {
     fieldType: 'Type *',
     fieldDescription: 'Description',
     isGateway: 'Inter-VLAN gateway',
-    isLivebox: 'ISP Box / Router',
+    isLivebox: 'Internet gateway',
     accessUrl: 'Access URL',
     runtimeType: 'Runtime environment',
     notSpecified: '— Not specified',
@@ -373,7 +373,7 @@ const LANGS = {
     fieldType: 'Tipo *',
     fieldDescription: 'Descripción',
     isGateway: 'Pasarela inter-VLAN',
-    isLivebox: 'Router / Box ISP',
+    isLivebox: 'Pasarela de Internet',
     accessUrl: 'URL de acceso',
     runtimeType: 'Entorno de ejecución',
     notSpecified: '— No especificado',