Certificates

• A4 landscape page with zero margins; everything is drawn on the page canvas (PdfContentByte): rectangles and circles for the frame and seal, showTextAligned(ALIGN_CENTER, ...) for centred text.
• Long names shrink until they fit: while (font.getWidthPoint(name, size) > maxWidth) size--;
• Bulk issue = one certificate row per line; "Print selected" puts them in one PDF, one page each.
• Verification: the QR holds {printdoc.public-base-url}/verify/{verify_code}; the code is random, so certificate numbers cannot be guessed.

SELECT certificate_no, recipient_name, course_title, issued_on, verify_code
FROM certificate WHERE verify_code = '...';

Files: service/CertificatePdfService.java, service/BusinessService.issueCertificates, templates/verify.html.