Feature request + contribution: Optional login + cloud sync for progress

[sujitanireddy]

First off—thanks for building this Progress Tracker. I’ve been using it and really like the clean UI + built-in spaced repetition flow.

Would you be open to adding an optional “Sign in” experience so a user’s progress can be synced to the cloud?

My plan:
• Auth: Email/password to start (OAuth like Google/GitHub later if desired)
• Cloud storage: Store the same progress JSON per user
• Sync behavior (local-first):
- Default stays localStorage when signed out
• When signed in:
- Load progress from cloud on login
- Auto-save updates to cloud when progress changes
- Data tools: Export/Import continue to work

Question: Can I build this and contribute a PR?

If this is something you’d accept, I’d love to implement it and open a PR.

A quick question so I can align with your preferred direction:
- Do you have a preferred backend (e.g., Supabase, Firebase, or something else)?

If you’re good with it, I can start with a minimal implementation (email auth + single user_progress doc/table) and keep the UI lightweight.

Thanks—happy to contribute!