chore(screener): add @xyflow/react + vitest test environment

package.json

@@ -10,9 +10,12 @@
     "deploy:nas": "node scripts/deploy-nas.cjs",
     "release:nas": "npm run build && npm run deploy:nas",
     "lint": "eslint .",
-    "preview": "vite preview"
+    "preview": "vite preview",
+    "test": "vitest",
+    "test:run": "vitest run"
   },
   "dependencies": {
+    "@xyflow/react": "^12.10.2",
     "leaflet": "^1.9.4",
     "react": "^18.2.0",
     "react-dom": "^18.2.0",
@@ -24,6 +27,9 @@
   },
   "devDependencies": {
     "@eslint/js": "^9.39.1",
+    "@testing-library/jest-dom": "^6.9.1",
+    "@testing-library/react": "^16.3.2",
+    "@testing-library/user-event": "^14.6.1",
     "@types/react": "^18.2.79",
     "@types/react-dom": "^18.2.25",
     "@vitejs/plugin-react": "^5.1.1",
@@ -31,7 +37,9 @@
     "eslint-plugin-react-hooks": "^7.0.1",
     "eslint-plugin-react-refresh": "^0.4.24",
     "globals": "^16.5.0",
+    "jsdom": "^25.0.1",
     "rimraf": "^6.1.2",
-    "vite": "^7.2.4"
+    "vite": "^7.2.4",
+    "vitest": "^2.1.9"
   }
 }