chore: add Vitest for testing and coverage support

- Introduced new test scripts in package.json: "test", "test:watch", and "test:coverage".
- Added Vitest and vite-tsconfig-paths as dependencies for improved testing capabilities.
- Updated pnpm-lock.yaml to reflect new dependencies and their versions.

package.json

@@ -13,6 +13,9 @@
     "dev": "next dev",
     "build": "next build",
     "start": "next start",
+    "test": "vitest run",
+    "test:watch": "vitest",
+    "test:coverage": "vitest run --coverage",
     "lint": "eslint",
     "prettier": "prettier --write ."
   },
@@ -37,12 +40,15 @@
     "@types/node": "^20",
     "@types/react": "^19",
     "@types/react-dom": "^19",
+    "@vitest/coverage-v8": "^4.0.18",
     "dotenv": "^17.2.3",
     "eslint": "^9",
     "eslint-config-next": "16.0.5",
     "eslint-config-prettier": "^10.1.8",
     "prettier": "^3.7.1",
     "tailwindcss": "^4",
-    "typescript": "^5"
+    "typescript": "^5",
+    "vite-tsconfig-paths": "^6.1.1",
+    "vitest": "^4.0.18"
   }
 }