Visually verifies a compiled LaTeX PDF — renders pages to images, runs structural checks (page count, figures present, fonts embedded, no overfull/underfull warnings), optionally diffs against a reference PDF (diff-pdf or SSIM via ImageMagick), and iterates compile-render-analyze-fix until the document passes or a budget is exhausted. Use ONLY when the user explicitly asks to verify, check, validate, or visually inspect the output.
