When the Dashboard switches between mobile and desktop modes, the batch

selection state gets all messed up. The internal model knows what's

supposed to be selected, but the checkboxes don't reflect it. The reason

is that the datagrid, behind the scenes, keeps up to two rendered copies

of the table: one for mobile, one for desktop. This means we have two

separate set of checkboxes to deal with, not one.
Now, whenever we switch modes, we re-apply the model's version of the

selection back to the page, ensuring it's always consistent.

Manually tested by going back-and-forth between modes, toggling

checkboxes each time. Verified that the model and checkboxes were always

in sync.
Unit tests unfortunately cannot be provided due to limitations in the

base DataGrid support, preventing the simulation of mobile/desktop mode.