Add unit tests for API client, stores, and utils

package.json

@@ -7,7 +7,9 @@
     "dev": "vite",
     "build": "tsc -b && vite build",
     "lint": "eslint .",
-    "preview": "vite preview"
+    "preview": "vite preview",
+    "test": "vitest",
+    "test:run": "vitest run"
   },
   "dependencies": {
     "@tanstack/react-query": "^5.90.20",
@@ -23,17 +25,23 @@
   "devDependencies": {
     "@eslint/js": "^9.39.1",
     "@tailwindcss/vite": "^4.1.18",
+    "@testing-library/jest-dom": "^6.9.1",
+    "@testing-library/react": "^16.3.2",
+    "@testing-library/user-event": "^14.6.1",
     "@types/node": "^24.10.1",
     "@types/react": "^19.2.5",
     "@types/react-dom": "^19.2.3",
+    "@types/testing-library__jest-dom": "^6.0.0",
     "@vitejs/plugin-react": "^5.1.1",
     "eslint": "^9.39.1",
     "eslint-plugin-react-hooks": "^7.0.1",
     "eslint-plugin-react-refresh": "^0.4.24",
     "globals": "^16.5.0",
+    "jsdom": "^27.4.0",
     "tailwindcss": "^4.1.18",
     "typescript": "~5.9.3",
     "typescript-eslint": "^8.46.4",
-    "vite": "^7.2.4"
+    "vite": "^7.2.4",
+    "vitest": "^4.0.18"
   }
 }