Refactored i18n configuration, replacing `DEFAULT_LOCALE` with `DEFAULT_LOCALE_FALLBACK` and enhancing environment-based locale validation. Improved cookie persistence for cart and wishlist, ensuring fallback handling for unauthenticated users.
Enhancements:
- Added `createProjectKey` utility for consistent project key generation.
- Reworked cart and wishlist composables (`useOrderOverwrite`, `useWishlistOverwrite`) to decouple product identifier and handle cookies robustly.
- Centralized `DEFAULT_LOCALE` logic for better maintainability.
- Refined `useOrderSync` and `useWishlistSync` for clean synchronization across auth states.
- Updated SCSS in hero and header styles for alignment corrections.
Breaking Changes: `DEFAULT_LOCALE` constant removed; replaced with runtime config and fallback logic. Consumers must adapt to `DEFAULT_LOCALE_FALLBACK` and `$appHelpers.DEFAULT_LOCALE`.
