fix(i18n): replace raw translation keys on panel screens (#7057)

Use valid translation keys on six panel screens, add the missing copy-failure and empty-value strings across all locales, and reject unresolved literal translation keys in the regression test.

internal/web/translation/ru-RU.json

@@ -40,6 +40,7 @@
   "indefinite": "Бесконечно",
   "unlimited": "Безлимит",
   "none": "Нет",
+  "empty": "Пусто",
   "qrCode": "QR-код",
   "info": "Информация",
   "edit": "Изменить",
@@ -47,6 +48,7 @@
   "reset": "Сброс",
   "noData": "Нет данных.",
   "copySuccess": "Скопировано",
+  "copyFail": "Не удалось скопировать",
   "sure": "Да",
   "encryption": "Шифрование",
   "transmission": "Транспорт",