chore: standardize ESM-first architecture and resolve all type/test/lint errors

vitest.config.mts

@@ -0,0 +1,24 @@
+import { defineConfig } from 'vitest/config';
+import react from '@vitejs/plugin-react';
+
+export default defineConfig({
+    plugins: [react()],
+    resolve: {
+        alias: {
+            'next/server': 'next/server.js',
+        },
+    },
+    ssr: {
+        noExternal: ['@mintel/next-utils', 'next-intl'],
+    },
+    test: {
+        environment: 'happy-dom',
+        globals: true,
+        exclude: ['**/node_modules/**', '**/.next/**', '**/dist/**'],
+        include: ['**/*.test.{ts,tsx}'],
+        coverage: {
+            provider: 'v8',
+            reporter: ['text', 'json', 'html'],
+        },
+    },
+});