add auth anonymous plugin

packages/auth/src/index.ts

@@ -2,6 +2,7 @@ import { db } from "@zendegi/db";
 import * as schema from "@zendegi/db/schema/auth";
 import { env } from "@zendegi/env/server";
 import { betterAuth } from "better-auth";
+import { anonymous } from "better-auth/plugins";
 import { drizzleAdapter } from "better-auth/adapters/drizzle";
 import { tanstackStartCookies } from "better-auth/tanstack-start";
 
@@ -15,7 +16,7 @@ export const auth = betterAuth({
   emailAndPassword: {
     enabled: true,
   },
-  plugins: [tanstackStartCookies()],
+  plugins: [tanstackStartCookies(), anonymous()],
   advanced: {
     database: {
       generateId: "uuid",