Selfhost - Modern PDF attachments silently fail to embed due to missing PdfParse module

Bug description When attaching a modern PDF (version 1.5+) to an invoice in the self-hosted version, the PDF silently fails to embed in the generated invoice PDF, even if "Embed Images/Documents" is enabled. This occurs because FPDI natively throws a PdfParserException when encountering PDFs > v1.4. In the App\Services\PdfMaker\PdfMerge class, the exception is caught, and the code attempts to downgrade the PDF by calling \Modules\Admin\Services\PdfParse::downgrade($file). However, this module class is not present in the self-hosted version, causing the class_exists() check to fail. As a result, the document embedding is completely skipped without any error logs. Steps to reproduce 1. Enable "Include attached images/pdfs in the invoice" in Settings -> Invoice Design. 2. Attach a PDF saved in format > 1.4 (e.g., a standard export from modern tools like Chrome or Word) to an invoice. 3. Click "View PDF" or send the invoice. 4. The attached PDF is …