alter table fulfillment_tasks
  add column if not exists assignee_account_id uuid references staff_accounts(id) on delete set null,
  add column if not exists accepted_at timestamptz,
  add column if not exists progress_note text not null default '',
  add column if not exists result_summary text not null default '',
  add column if not exists completed_at timestamptz;

create index if not exists idx_tasks_assignee_status on fulfillment_tasks(assignee_account_id, status, updated_at desc);
