Enable alert resolution policy

Allow moderators to resolve rate limit alerts by adding UPDATE policy on rate_limit_alerts and granting UPDATE to authenticated users. This completes enabling the Resolve action for alerts.

supabase/migrations/20251111011244_62ebd15f-c783-489a-9088-9dc3e0268f8e.sql

@@ -0,0 +1,22 @@
+-- Add UPDATE policy for resolving alerts
+CREATE POLICY "Moderators can resolve alerts"
+ON public.rate_limit_alerts
+FOR UPDATE
+TO authenticated
+USING (
+  EXISTS (
+    SELECT 1 FROM public.user_roles
+    WHERE user_id = auth.uid()
+    AND role IN ('admin', 'moderator', 'superuser')
+  )
+)
+WITH CHECK (
+  EXISTS (
+    SELECT 1 FROM public.user_roles
+    WHERE user_id = auth.uid()
+    AND role IN ('admin', 'moderator', 'superuser')
+  )
+);
+
+-- Grant UPDATE permission
+GRANT UPDATE ON public.rate_limit_alerts TO authenticated;