I need an experienced Firebase engineer to configure a brand-new project in the Firebase Console and wire up all authentication options in a single mobile / web codebase I will provide. The core task is to get Firebase Authentication working smoothly and securely. Deliverables I expect • Firebase Console created, project settings filled in, and all keys shared back to me • Email + password sign-up/sign-in fully tested • Social media login (Google, Facebook, Apple) enabled and verified inside Firebase and in code • Phone number authentication with SMS verification working in both development and production modes Acceptance criteria 1. No console errors or deprecated API warnings during auth flows 2. Correct user objects returned on every successful login method 3. Clear, step-by-step hand-off notes so I can maintain the console settings myself in future I have the frontend ready; I simply need your Firebase mastery to plug everything together quickly and cleanly.