Add category and subcategory columns to the Excel export

Customers have raised the need to include category and subcategory information for items when exporting reports to Excel (as well as to third-party tools such as Monday). Currently, this data is not always included in exports, which complicates the grouping of expense items, the calculation of totals by subcategory, and internal sorting for budget tracking. The development team has confirmed the validity of this request and plans to add these columns in an upcoming update.