Plan a Week That Already Has Shifts

Opening the plan page for a week that already has shifts shows them on the calendar

Navigate to the plan page for that week and select the location — the existing shift shows up right away. Dismiss the start dialog with 'Start fresh' — the existing shift stays visible since it's not part of the fresh draft. Publishing is disabled — there are no new draft shifts to publish, only the pre-existing one. The existing shift isn't editable from the plan page — clicking it does nothing.