fix(two-factor): incorrect default OTP period & fix incorrect docs (#3231)

* docs(2fa): fix incorrect period

* fix: default period is 3 minutes

* Update packages/better-auth/src/plugins/two-factor/index.ts

Co-authored-by: cubic-dev-ai[bot] <191113872+cubic-dev-ai[bot]@users.noreply.github.com>

* chore: lint

---------

Co-authored-by: cubic-dev-ai[bot] <191113872+cubic-dev-ai[bot]@users.noreply.github.com>

docs/content/docs/plugins/2fa.mdx

@@ -393,7 +393,7 @@ these are options for TOTP.
         default: 6,
     },
     period: {
-        description: "The period for otp in seconds.",
+        description: "The period for totp in seconds.",
         type: "number",
         default: 30,
     },
@@ -411,9 +411,9 @@ these are options for OTP.
         type: "function",
     },
     period: {
-        description: "The period for otp in seconds.", 
+        description: "The period for otp in minutes.", 
         type: "number",
-        default: 30,
+        default: 3,
     },
   }}
   />

packages/better-auth/src/plugins/two-factor/index.ts

@@ -296,7 +296,7 @@ export const twoFactor = (options?: TwoFactorOptions) => {
 						 */
 						deleteSessionCookie(ctx, true);
 						await ctx.context.internalAdapter.deleteSession(data.session.token);
-						const maxAge = options?.otpOptions?.period || 60 * 5; // 5 minutes
+						const maxAge = (options?.otpOptions?.period ?? 3) * 60; // 3 minutes
 						const twoFactorCookie = ctx.context.createAuthCookie(
 							TWO_FACTOR_COOKIE_NAME,
 							{