If a Tree becomes mangled, what is the Gramps Web workflow for clearing the Tree data and re-uploading the data from the Desktop master tree? (In Gramps for Desktops, you just create a new tree in the Family Trees → Manage Family Trees… dialog. How is Gramps Web different?)
I assume that there will already be user accounts and customizations that you won’t want to lose.
It’s currently not easy. That’s because I am a bit scared of making it too easy.
I guess the most efficient way at present would be to synchronize with Gramps Desktop, then switch to a new empty db in Desktop and run the sync again. It will report all objects as deleted and clicking apply will delete them.
If somebody volunteers to try it out and it works, we can document it