[Blocker] fix: implement proper XLSX export using exceljs library

## GitHub Update **Repository:** [MKWcorp/drwprime](https://github.com/MKWcorp/drwprime) **Author:** MKWcorp **Date:** 2/7/2026, 12:42:29 PM **Commit:** [`a6ed9be`](https://github.com/MKWcorp/drwprime/commit/a6ed9bec4508489222b6fcb21abd452a682d243e) ### Commit Message fix: implement proper XLSX export using exceljs library - Install exceljs for native XLSX generation - Replace TSV export with proper Excel format - Add styled header with gold background - Set proper column widths for better readability - Export as .xlsx format to avoid Excel warnings - Add Export Excel button with icon in report page header --- _This story was imported from historical commits._