Add token valification unit test

vitest.config.ts

@@ -1,10 +1,14 @@
-import { defineConfig } from "vitest/config";
+import { defineConfig } from 'vitest/config';
+import { resolve } from 'node:path';
 
 export default defineConfig({
   test: {
     coverage: {
       exclude: ['**/node_modules/**', 'docs/**', '**/.next/**'],
-      provider: "v8",
+      provider: 'v8',
     },
   },
+  resolve: {
+    alias: [{ find: '@', replacement: resolve(__dirname, './frontend') }],
+  },
 });