Add a BulkAction to the EmailTemplateResource table. Cashier/marketer
selects N rows, picks from_locale + to_locales (multi), and DeepL
translates all of them in the background via AutomatedTranslation.
Variables stay intact thanks to the protectVariables wrapper in
dashed-translations v4.1.4.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>