CREATE TABLE trucks (
  id         UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  truck_no   TEXT NOT NULL UNIQUE,
  carrier    TEXT,
  active     BOOLEAN NOT NULL DEFAULT true,
  created_at TIMESTAMPTZ NOT NULL DEFAULT now()
);

ALTER TABLE incidents ADD COLUMN truck_id UUID REFERENCES trucks(id);
CREATE INDEX incidents_truck_id_idx ON incidents(truck_id);

ALTER TABLE trucks ENABLE ROW LEVEL SECURITY;
CREATE POLICY "trucks_read"      ON trucks FOR SELECT USING (true);
CREATE POLICY "trucks_admin_all" ON trucks FOR ALL    USING (auth_user_role() = 'admin');