Merge pull request #1 from bsozer06/dev_unit_tests_1

feat: add testing framework and initial tests for API and context

feat: add core components and context for e-commerce application

- Implemented Button, Input, and LoadingSpinner components for UI.
- Created CartItemCard and ProductCard components for displaying cart items and products.
- Developed SearchBar for product searching functionality.
- Built Header component for navigation and user authentication.
- Added ProductList component to display products with loading and error handling.
- Established AuthContext and CartContext for managing authentication and cart state.
- Created custom hooks (useAuth, useCart, useFetch, useProducts) for context consumption and data fetching.
- Developed pages: CartPage, HomePage, LoginPage, ProductDetailPage for application routing.
- Integrated Tailwind CSS for styling and responsive design.
- Configured TypeScript for type safety and improved developer experience.
- Set up Vite for fast development and build process.