Add regularization to Laplacian and preconditioners for `ConjugateGradientPoissonSolver`#3848

Draft

glwagner wants to merge 14 commits intomainfrom glw/regularized-laplacian

+105-52

Commits on Oct 17, 2024

Commits on Oct 18, 2024

Change sign of regularization, plus cleaner code design
glwagner
committed

Commits on Oct 22, 2024

Commits on Dec 13, 2024

Merge branch 'main' into glw/regularized-laplacian
glwagner
authored