chore(format): set up Prettier

package.json

@@ -10,7 +10,9 @@
     "test": "vitest",
     "test:run": "vitest run",
     "lint": "eslint .",
-    "lint:fix": "eslint . --fix"
+    "lint:fix": "eslint . --fix",
+      "format": "prettier . --write",
+      "format:check": "prettier . --check"
   },
   "dependencies": {
     "pinia": "^3.0.4",
@@ -30,6 +32,7 @@
     "generate-license-file": "^4.2.1",
     "globals": "^17.9.0",
     "jsdom": "^29.1.1",
+    "prettier": "^3.9.6",
     "vite": "^8.0.10",
     "vite-plugin-html": "^3.2.2",
     "vitest": "^4.1.7"