Add vitest setup and puzzleUtils tests

vitest.config.js

@@ -0,0 +1,16 @@
+import { defineConfig } from 'vitest/config'
+import vue from '@vitejs/plugin-vue'
+import path from 'path'
+
+export default defineConfig({
+  plugins: [vue()],
+  test: {
+    globals: true,
+    environment: 'jsdom',
+  },
+  resolve: {
+    alias: {
+      '@': path.resolve(__dirname, './src')
+    }
+  }
+})