Cart Checkout

User story

As a user, I want to easily view and manage my selected items in a checkout cart, ensuring I have control over my order before finalizing the purchase.

Acceptance criteria

• A cart icon in the navigation bar updates with the number of items added.
• Clicking the cart icon opens a list of selected items with details such as restaurant name, item count, and individual prices.
• The cart displays a subtotal, delivery cost (if applicable), and a total amount.
• A "Go to Checkout" button is available but does not perform any real checkout actions (mocked UI).