Subprincples now have a default of false in the affirmative column.

We do now need to be able to flip that to :true and add the evidence.

db/migrate/20240425091331_alter_table_subprincipleitems.rb

@@ -0,0 +1,5 @@
+class AlterTableSubprincipleitems < ActiveRecord::Migration[7.1]
+  def change
+    change_column_default :subprincipleitems, :affirmative, from: nil, to:  false
+  end
+end