feat(admin): finalizing modular refactoring with testing suite and UI polish

frontend/package.json

@@ -6,7 +6,8 @@
     "dev": "next dev",
     "build": "next build",
     "start": "next start",
-    "lint": "next lint"
+    "lint": "next lint",
+    "test": "vitest"
   },
   "dependencies": {
     "axios": "^1.15.0",
@@ -27,10 +28,15 @@
     "@types/node": "^20",
     "@types/react": "^19",
     "@types/react-dom": "^19",
+    "@testing-library/jest-dom": "^6.5.0",
+    "@testing-library/react": "^16.0.1",
     "eslint": "^9",
     "eslint-config-next": "15.0.0",
+    "jsdom": "^25.0.1",
     "postcss": "^8",
     "tailwindcss": "^3.4.1",
-    "typescript": "^5"
+    "typescript": "^5",
+    "vitest": "^2.1.2",
+    "@vitejs/plugin-react": "^4.3.2"
   }
 }