fix: resolve i18n issues - URL duplication, translation loading, and caching

- Fix URL path duplication when clicking logo (added missing leading slash)
- Use network-first caching for translation files in service worker
- Add missing translation keys (common.close, upload.clearFiles) to all languages
- Add Dutch (nl) language support to URL regex patterns
- Bump service worker cache version to v8

public/locales/fr/common.json

@@ -66,7 +66,8 @@
     "pdfOrImages": "PDF ou images",
     "filesNeverLeave": "Vos fichiers restent sur votre appareil.",
     "addMore": "Ajouter d’autres fichiers",
-    "clearAll": "Tout effacer"
+    "clearAll": "Tout effacer",
+    "clearFiles": "Effacer les fichiers"
   },
   "loader": {
     "processing": "Traitement en cours..."
@@ -226,7 +227,8 @@
     "error": "Erreur",
     "success": "Succès",
     "file": "Fichier",
-    "files": "Fichiers"
+    "files": "Fichiers",
+    "close": "Fermer"
   },
   "about": {
     "hero": {