feat(admin): streamline group management

apps/web/package.json

@@ -29,6 +29,7 @@
   },
   "devDependencies": {
     "@tailwindcss/postcss": "^4.2.1",
+    "@testing-library/react": "^16.3.2",
     "@types/d3-geo": "^3.1.1",
     "@types/leaflet": "^1.9.22",
     "@types/node": "^25.0.3",
@@ -37,6 +38,7 @@
     "@types/topojson-client": "^3.1.5",
     "eslint": "^9.39.4",
     "eslint-config-next": "^16.2.1",
+    "jsdom": "^30.0.1",
     "tailwindcss": "^4.2.1",
     "typescript": "^5.9.3",
     "vitest": "^4.1.0"