As https://secure.phabricator.com/T7410 is not going anywhere, it's necessary to delete empty/unused workboards server-side, to declutter phabricator.wikimedia.org and make it more performant.
- Devise DB query to list workboards which have 100 % items in the "backlog" column.
- Identify DB query or server-side command to delete workboards.
- Proceed to delete the workboards.
- Figure our a smarter query to also list workboards which have less than X (1?) item in their "history", including column renames/additions and column changes.
- Disable, rather than delete, the workboards which are unused but may contain some data
- Make the project details default menu item for all the projects where the workboard is the default item but has been deleted or disabled