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/en/common.json

@@ -66,7 +66,8 @@
     "pdfOrImages": "PDFs or Images",
     "filesNeverLeave": "Your files never leave your device.",
     "addMore": "Add More Files",
-    "clearAll": "Clear All"
+    "clearAll": "Clear All",
+    "clearFiles": "Clear Files"
   },
   "loader": {
     "processing": "Processing..."
@@ -226,7 +227,8 @@
     "error": "Error",
     "success": "Success",
     "file": "File",
-    "files": "Files"
+    "files": "Files",
+    "close": "Close"
   },
   "about": {
     "hero": {