Flesh out work items in the UI

db/migrate/20231008144635_rename_work_item_columns.rb

@@ -0,0 +1,6 @@
+class RenameWorkItemColumns < ActiveRecord::Migration[7.1]
+  def change
+    rename_column :work_items, :start_time, :available_from
+    rename_column :work_items, :due_date, :due_at
+  end
+end

db/migrate/20231008145328_add_completion_time_to_work_item.rb

@@ -0,0 +1,5 @@
+class AddCompletionTimeToWorkItem < ActiveRecord::Migration[7.1]
+  def change
+    add_column :work_items, :completed_at, :datetime
+  end
+end