This commit refactors the `main.go` file in the API directory, as well as the related models in the `models.go` file. The changes include: - Reordering imports and removing unnecessary imports - Fixing error messages to be more descriptive - Handling database connections more efficiently with deferred closures - Handling errors and returning appropriate error responses - Adding proper JSON bindings for POST requests - Adding new views in the database scripts for aggregated statistics and daily user statistics No changes were made to imports and requires.