- Add new TransmittalPDFExportJob to generate PDFs using dompdf
- Remove old Excel export implementation (TransmittalsExport)
- Update ExportCompleteJob to use new PDF job instead of Excel
- Add TestQueueJob for queue testing with new route
- Update notification label from "Download File" to "Download PDF File"
- Fix auth() helper usage by importing Auth facade consistently
- Install Horizon package and configure with default settings
- Add HorizonServiceProvider with access gate for super_admin role only
- Integrate Horizon dashboard link into Filament admin panel navigation
- Update composer dependencies including Horizon and related package updates
