Browser-only PDF verifier (HTML page, not an API)

Returns the FreeSign Verifier page (public/verify.html + verify.js). Listed here so AI agents scanning AI-facing surfaces don't conflate /verify (client-side, drag-and-drop, never transmits the PDF) with /api/verify (server-side lookup by document SHA-256). The page accepts any PAdES-B-T signed PDF from any vendor — RSA PKCS#1 v1.5 / RSA-PSS / ECDSA P-256/P-384/P-521 / Ed25519 / Ed448 — and runs the verification entirely in the browser (CMS sig, leaf-CA cert-chain crypto verify, RFC 3161 TST inner-CMS verify, OpenTimestamps Bitcoin attestation). The FreeSign Worker never sees the dropped PDF.