Revert RLS policies for signatures

supabase/migrations/20251026150621_bda97e31-e75f-4dc9-90fc-5fd0454e600a.sql

@@ -0,0 +1,16 @@
+-- Revert to public access policies
+DROP POLICY IF EXISTS "Only authenticated users can view all signature data" ON public.petition_signatures;
+DROP POLICY IF EXISTS "Anyone can sign the petition" ON public.petition_signatures;
+
+-- Restore original public access
+CREATE POLICY "Anyone can view signatures"
+ON public.petition_signatures
+FOR SELECT
+TO anon, authenticated
+USING (true);
+
+CREATE POLICY "Anyone can sign the petition"
+ON public.petition_signatures
+FOR INSERT
+TO anon, authenticated
+WITH CHECK (true);