Fix SQL queries for playlists

db.go

 		return false, err
 	}
 	query := `
-	INSERT INTO public.round_playlist pl
-	SELECT r.id, json_to_array($2)
+	INSERT INTO public.round_playlist
+	SELECT r.id, ARRAY(SELECT e::text FROM json_array_elements($2::json) e)
 	FROM public.round r 
 	WHERE r.section = $1
-	ON CONFLICT (pl.round_id) DO UPDATE SET tracks = EXCLUDED.tracks`
+	ON CONFLICT (round_id) DO UPDATE SET tracks = EXCLUDED.tracks`
+
 	res, err := db.database.Exec(query, sectionName, tracksJson)
 
 	if err != nil {

sql/database.sql

     tracks text[],
     CONSTRAINT round_id FOREIGN KEY (round_id)
         REFERENCES public.round (id)
-);
+);
+ALTER TABLE public.round_playlist 
+ADD CONSTRAINT round_id_unique UNIQUE(round_id);

web/index.html

             <input type="password" name="password" class="form-control" placeholder="Password" required>
             <div class="checkbox">
                 <label>
-                    <input type="checkbox" name="remember-me" value="remember-me"> Remember me
+                    <input type="checkbox" name="remember-me" value="remember-me" checked> Remember me
                 </label>
             </div>
             <button class="btn btn-lg btn-primary btn-block" type="submit">Sign in</button>