CREATE TABLE IF NOT EXISTS public.user_progress ( id bigint GENERATED ALWAYS AS IDENTITY PRIMARY KEY, user_id uuid REFERENCES auth.users(id) ON DELETE CASCADE NOT NULL, subject text NOT NULL, question_id integer NOT NULL, last_result text NOT NULL, attempts integer DEFAULT 1 NOT NULL, wrong_count integer DEFAULT 0 NOT NULL, updated_at timestamptz DEFAULT now() NOT NULL, UNIQUE(user_id, subject, question_id) ); ALTER TABLE public.user_progress ENABLE ROW LEVEL SECURITY; CREATE POLICY "Users manage own progress" ON public.user_progress FOR ALL USING (auth.uid() = user_id) WITH CHECK (auth.uid() = user_id);