Abdulbaset1/XcelTrack---Cell-Level-Version-Control-for-Excel ? reverse-engineered prompt

Build me a web app called XcelTrack that helps people keep track of changes in Excel files at the cell level, so it feels like version control for spreadsheets. I want a simple React frontend and a backend that stores data in Postgres and handles syncing between users.

The app should let someone open a spreadsheet, see what changed in a clear way, compare versions, and understand who changed what. It should also have admin tools for adding users and syncing them, and if the Firebase service account key is available, use that for the admin flow, otherwise still run as best it can locally.

Please make sure the frontend and backend both run separately, with the frontend on port 3000 and the server on port 5000. Keep the UI clean and easy to use, and if you need to look up any current docs online while setting it up, go ahead.