See #31164. Upstream code at https://github.com/flatsurf/sage-flatsurf and https://www.labri.fr/perso/vdelecro/sage-flatsurf.

Depends on #31224

CC: @mkoeppe

Component: packages: optional

Author: Vincent Delecroix

Branch/Commit: fba93c5

Reviewer: Matthias Koeppe

Issue created by migration from https://trac.sagemath.org/ticket/31240