Puppeteer watermark

Most advice about adding a watermark in HTML is incomplete. It shows you how to place faint text over a page with position: fixed, lower the opacity, maybe disable selection, and call it done. That works for browser display. It does not give you durable document protection, and it often falls apart the moment you send that HTML through a PDF renderer. That gap matters. If the document needs a visible DRAFT, CONFIDENTIAL, or account-specific stamp that survives pagination, page breaks, an