You should be able to emit COLLATE ... on an INT column.

Hmm, this is weird to me. I'd expect that an archived column keeps its sequence, and that it's never possible to have two columns with sequence, say, 15. Let me look at the rest of the diff...

Let's make this withStatuses(). I've generally been having better luck building UIs and Conduit around that.

Particularly, users and UIs often want to get all "open" or "closed" things, but this can correspond to several statuses. So we either need to define magic statuses (which we used to do, but which I think is super gross/messy) or have a multi-value API on the Query (which I've been doing more recently, and which I think works better).

This has also made it easy to move advanced search to just use a list of checkboxes, which is easy for users to understand and works like everyone expects.

I think this is OK for now, but in the mid term we should move away from it and have a contextual delete action. Specifically:

• The "gear" icon ('edit column') should be called "Column Settings" or something and take you to a standard "column details" page, instead of directly to an edit form.
• The "column details" page would have an timeline/edit history once we use applicationtransactions (e.g. who deleted the column and when? who renamed it and when?), detailed information, and then actions ("Edit Column", "Delete Column").
• The current "Edit Column" page would be behind the "Edit Column" link.
• A new confirm dialog would be behind the "Delete Column" link.

We should just call isDefaultColumn() on each column instead of doing logic here, we might have non-first default columns in the future.

Or, add withIsDefault(false) to the Query or something.

I'm hesitant about putting this in the web UI, although we'll probably need "move all..." eventually. Particularly, if a column has like 10,000 tasks, this will take a long-ass time and probably timeout and fail. This will also send a ton of email. Finally, it's not a great default action -- it's pretty reasonable, but often it's probably not really what the user would prefer.

A much easier alternative which has fewer problems is to prevent users from deleting columns which contain tasks -- just fail with "This column still has some tasks in it. Before you can delete a column, you must move all the tasks out of it.".

This is a little more cumbersome, but way way simpler, and maybe a better approach?

Could we just leave this as-is, and still consider deleted columns, so there's always exactly one sequence over all the columns?