- Added a new `completionCount` field to the DayProduction model to track the number of completed productions.
- Updated the FalukantService to aggregate completed productions using the new `completionCount` field, improving accuracy in production statistics.
- Introduced new vocabulary training features in VocabLessonView, including options to mark vocabulary as difficult and track remaining hard vocabulary, enhancing user engagement and learning effectiveness.
- Updated localization files for German and English to support new vocabulary training features, ensuring a consistent user experience across languages.