Added a "Details" column to the grid in `Index.cshtml` with a button linking to the new invoice details page. The button dynamically generates the URL using the invoice ID.
Created `Details.cshtml` to display detailed invoice information, including metadata such as seller, buyer, amounts, and dates. Added a back button and error handling for missing invoices.
Introduced `DetailsModel` in `Details.cshtml.cs` to fetch invoice data using `AppDbContext`. Implemented the `OnGetAsync` method to retrieve data asynchronously and handle cases where the invoice is not found.
Added new navigation menu items in `_Layout.cshtml` for "Rechnungen" (Invoices) and "PDF hochladen" (Upload PDF) with icons, paths, and selection logic.
Created a new Razor Page `Index.cshtml` to display imported invoices using a `DataGrid` with features like filtering, paging, and column formatting. Added a conditional message for when no invoices are available.
Implemented the `IndexModel` class in `Index.cshtml.cs` to handle backend logic, including fetching and sorting invoices from the database using `AppDbContext`.
