chore: add prettier as a dev dependency

Author: c-c-epr

package-lock.json

@@ -21,6 +21,7 @@
   "devDependencies": {
     "@cloudflare/vitest-pool-workers": "^0.12.4",
     "@types/node": "^25.6.0",
+    "prettier": "^3.8.3",
     "typescript": "^6.0.3",
     "vitest": "~3.2.0",
     "wrangler": "^4.85.0"