Renames `AuthStruct` to `AuthModel` and `ProductStruct` to `ProductModel` to align with a consistent data model naming convention.
Updates all relevant imports, type declarations, and method signatures across the application to reflect these changes, improving codebase clarity and maintainability.
Includes minor code style improvements and refactorings in other components.
Moves page files from verbose `*_page` named directories to simpler, more organized paths.
This includes:
- Renaming top-level pages (e.g., `home_page` to `home`, `login_page` to `login`).
- Nesting related pages under common directories (e.g., `product_form_page` and `product_list_page` are now under `product/`).
The update improves project organization, reduces verbosity in file paths, and enhances overall maintainability.
