feat: re-introduce regression testing suite with pnpm

vitest.config.ts

@@ -0,0 +1,18 @@
+import { defineConfig } from 'vitest/config';
+import react from '@vitejs/plugin-react';
+import path from 'path';
+
+export default defineConfig({
+    plugins: [react()],
+    test: {
+        environment: 'jsdom',
+        globals: true,
+        setupFiles: ['./src/tests/setup.ts'],
+        exclude: ['**/node_modules/**', '**/tests/e2e/**', '**/dist/**'],
+    },
+    resolve: {
+        alias: {
+            '@': path.resolve(__dirname, './src'),
+        },
+    },
+});