Only approved users from your private Google Sheet can open the map, browse layers, add overlays, and upload their own GIS files. This keeps the experience premium, gated, and intentional even in a static single file build.
This version gives you a polished local account layer so a visitor can create an identity, save a name, and feel the product is alive even before a real backend is added. When you are ready, this screen can later be connected to Supabase, Firebase, Clerk, Auth0, or your own API.