feat: add API endpoints for downloading certificate and audit log PDFs (#3025)

Add V2 API routes to download an envelope's certificate and audit log
separately, and align the internal cert/audit log downloads to use
envelopeId.

Enforces document visibility via getEnvelopeWhereInput and loads field
signatures so certificates render correctly.

apps/remix/app/routes/_authenticated+/t.$teamUrl+/documents.$id.logs.tsx

@@ -153,11 +153,11 @@ export default function DocumentsLogsPage({ loaderData }: Route.ComponentProps)
           <div className="mt-4 flex w-full flex-row sm:mt-0 sm:w-auto sm:self-end">
             <DocumentCertificateDownloadButton
               className="mr-2"
-              documentId={document.id}
+              envelopeId={document.envelopeId}
               documentStatus={document.status}
             />
 
-            <DocumentAuditLogDownloadButton documentId={document.id} />
+            <DocumentAuditLogDownloadButton envelopeId={document.envelopeId} />
           </div>
         </div>
       </div>