feat: add unit tests and CI configuration

package.json

@@ -7,7 +7,9 @@
     "build": "next build --webpack",
     "start": "next start",
     "lint": "next lint",
-    "type-check": "tsc --noEmit"
+    "type-check": "tsc --noEmit",
+    "test": "vitest run",
+    "test:watch": "vitest"
   },
   "dependencies": {
     "@ciphera-net/ui": "^0.0.78",
@@ -44,16 +46,21 @@
   },
   "devDependencies": {
     "@tailwindcss/typography": "^0.5.19",
+    "@testing-library/jest-dom": "^6.9.1",
+    "@testing-library/react": "^16.3.2",
     "@types/d3-scale": "^4.0.9",
     "@types/node": "^20.14.12",
     "@types/react": "^18.3.3",
     "@types/react-dom": "^18.3.0",
     "@types/react-simple-maps": "^3.0.6",
+    "@vitejs/plugin-react": "^5.1.4",
     "autoprefixer": "^10.4.19",
     "eslint": "^9.39.2",
     "eslint-config-next": "^16.1.1",
+    "jsdom": "^28.1.0",
     "postcss": "^8.4.40",
     "tailwindcss": "^3.4.7",
-    "typescript": "5.9.3"
+    "typescript": "5.9.3",
+    "vitest": "^4.0.18"
   }
 }