Fork channel

Create a new channel as a copy of main.

Rename channel

Rename main to:

Delete channel

Delete main? This cannot be undone.

upgrade-58.sql
alter table Jobsets alter column nixExprInput drop not null;
alter table Jobsets alter column nixExprPath drop not null;
alter table Jobsets add column type integer default 0;
alter table Jobsets add column flake text;
alter table Jobsets add check ((type = 0) = (nixExprInput is not null and nixExprPath is not null));
alter table Jobsets add check ((type = 1) = (flake is not null));
alter table JobsetEvals add column flake text;