mathlib

73562699 - feat(linear_algebra/affine_space/basis): upgrade `affine_basis.coords` to an affine map (#10452)

feat(linear_algebra/affine_space/basis): upgrade `affine_basis.coords` to an affine map (#10452) Formalized as part of the Sphere Eversion project. Co-authored-by: Johan Commelin <johan@commelin.net>