The `Expense` entity and its associated API endpoints have been updated, and a new `ExpenseShare` entity with a corresponding DAO has been added.
The `MainViewModel` now includes logic to fetch expenses from the server upon successful session validation. The `DashboardScreen` has been updated to display a list of expenses using a `LazyColumn` and a new `ExpenseItem` component. Additionally, the `APIService` has been expanded to include CRUD operations for expenses and user information.