feat: replace Excel export with PDF export for transmittals

- 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

app/Jobs/TestQueueJob.php

@@ -0,0 +1,28 @@
+<?php
+
+namespace App\Jobs;
+
+use Illuminate\Bus\Queueable;
+use Illuminate\Contracts\Queue\ShouldQueue;
+use Illuminate\Foundation\Bus\Dispatchable;
+use Illuminate\Queue\InteractsWithQueue;
+use Illuminate\Queue\SerializesModels;
+use Illuminate\Support\Facades\Log;
+
+class TestQueueJob implements ShouldQueue
+{
+    use Dispatchable;
+    use InteractsWithQueue;
+    use Queueable;
+    use SerializesModels;
+
+    public function __construct()
+    {
+    }
+
+    public function handle(): void
+    {
+        Log::info('TestQueueJob executed');
+    }
+}
+