test: change vitest config (#7)

Bootstrap mínimo do harness Vitest para o p2pix-front-end. Adiciona configuração, polyfills de DOM, e cobertura inicial de utils + 1 componente simples — apenas o que roda contra `develop` sem dependências
  externas.

Co-authored-by: Arthur Abeilice <afa7789@gmail.com>
Reviewed-on: https://git.p2pix.co/doiim/p2pix-front-end/pulls/7

package.json

@@ -12,7 +12,10 @@
     "lint:fix": "eslint --fix",
     "format": "prettier --write \"src/**/*.{ts,vue,json}\"",
     "format:check": "prettier --check \"src/**/*.{ts,vue,json}\"",
-    "wagmi:gen": "wagmi generate"
+    "wagmi:gen": "wagmi generate",
+    "test": "vitest run --passWithNoTests",
+    "test:watch": "vitest",
+    "test:coverage": "vitest run --coverage"
   },
   "dependencies": {
     "@floating-ui/vue": "^1.1.11",