CREATE TABLE IF NOT EXISTS public.activity_resource_assignments (
  id                  uuid     PRIMARY KEY DEFAULT gen_random_uuid(),
  activity_id         uuid     NOT NULL REFERENCES public.activities(id) ON DELETE CASCADE,
  resource_id         uuid     NOT NULL REFERENCES public.resources(id) ON DELETE CASCADE,
  utilization_minutes numeric  NOT NULL DEFAULT 0,
  units               numeric  NOT NULL DEFAULT 1,
  scenario            text     NOT NULL DEFAULT 'actual' CHECK (scenario IN ('actual','automated'))
);

ALTER TABLE public.activity_resource_assignments ENABLE ROW LEVEL SECURITY;

CREATE POLICY "all_assignments" ON public.activity_resource_assignments
  FOR ALL USING (auth.uid() IS NOT NULL)
  WITH CHECK (auth.uid() IS NOT NULL);