feat(Diary): implement quick create functionality for training days and enhance localization

- Added a new button for quick creation of training days in the DiaryView, improving user experience.
- Implemented logic to find the next available training slot across groups and create a training day entry.
- Enhanced localization by adding new keys for quick create messages in multiple languages, ensuring better accessibility for users.
- Updated the DiaryManager to handle quick create operations and clear errors effectively.

scripts/generate-mobile-i18n.js

@@ -5,7 +5,7 @@
  * Source of truth: `frontend/src/i18n/locales/*.json`
  *
  * Output:
- * - `mobile-app/shared/src/commonMain/kotlin/de/tt_tagebuch/shared/i18n/MobileStrings.kt`
+ * - `mobile-app/shared/src/commonMain/kotlin/de/tsschulz/tt_tagebuch/shared/i18n/MobileStrings.kt`
  *
  * Notes:
  * - German (`de`) is the canonical key set.
@@ -25,6 +25,7 @@ const OUT = path.join(
   'commonMain',
   'kotlin',
   'de',
+  'tsschulz',
   'tt_tagebuch',
   'shared',
   'i18n',