test: add cypress sample code

frontend/package.json

@@ -7,7 +7,8 @@
     "dev": "vite",
     "build": "tsc && vite build",
     "lint": "eslint . --ext ts,tsx --report-unused-disable-directives --max-warnings 0",
-    "preview": "vite preview"
+    "preview": "vite preview",
+    "cy:test": "cypress run --headed --no-exit"
   },
   "dependencies": {
     "axios": "^1.6.8",
@@ -22,6 +23,7 @@
     "@typescript-eslint/eslint-plugin": "^6.14.0",
     "@typescript-eslint/parser": "^6.14.0",
     "@vitejs/plugin-react": "^4.2.1",
+    "cypress": "^13.7.1",
     "eslint": "^8.55.0",
     "eslint-plugin-react-hooks": "^4.6.0",
     "eslint-plugin-react-refresh": "^0.4.5",