feat: support 2fa for document completion (#2063)

Adds support for 2FA when completing a document, also adds support for
using email for 2FA when no authenticator has been associated with the
account.

packages/lib/server-only/2fa/email/generate-2fa-token-from-email.ts

@@ -0,0 +1,23 @@
+import { generateHOTP } from 'oslo/otp';
+
+import { generateTwoFactorCredentialsFromEmail } from './generate-2fa-credentials-from-email';
+
+export type GenerateTwoFactorTokenFromEmailOptions = {
+  documentId: number;
+  email: string;
+  period?: number;
+};
+
+export const generateTwoFactorTokenFromEmail = async ({
+  email,
+  documentId,
+  period = 30_000,
+}: GenerateTwoFactorTokenFromEmailOptions) => {
+  const { secret } = generateTwoFactorCredentialsFromEmail({ email, documentId });
+
+  const counter = Math.floor(Date.now() / period);
+
+  const token = await generateHOTP(secret, counter);
+
+  return token;
+};