Stirling-PDF Server-Side Request Forgery via /api/v1/convert/url/pdf WeasyPrint Subprocess

Stirling-PDF's POST /api/v1/convert/url/pdf endpoint (ConvertWebsiteToPDF.java) was not updated with the CustomHtmlSanitizer/SsrfProtectionService SSRF protections that were added to three sibling conversion endpoints (html/pdf, file/pdf, markdown/pdf). The endpoint validates only that the initial requested URL resolves to a public IP, then fetches the page's HTML server-side and hands it, unsanitized, to a WeasyPrint subprocess. Embedded resource references in the fetched HTML (e.g. ``) are fetched by WeasyPrint with no per-resource SSRF filtering, allowing an attacker-controlled page to cause the server to retrieve cloud metadata endpoints or internal network resources and leak their contents back into the generated PDF.