- Enhanced User model tests with creation, registration status, password hashing, and unique username checks.
- Added extensive tests for VerificationCode model including creation, uniqueness, and relation to User.
- Implemented Category model tests covering creation, uniqueness, and string representation.
- Expanded Product model tests to include creation, default values, VAT calculations, and deletion behavior.
- Introduced StockReservation and StockReservationItem model tests for creation, status checks, and unique constraints.
- Developed Cart and CartItem model tests focusing on creation, total calculations, and item uniqueness.
- Added Order and OrderItem model tests for creation, status management, and string representation.
- Included SavedPaymentMethod and ShippingAddress model tests for creation, default settings, and ordering.