Drop hosted rate_limits and global_prompts policies by catalog

Production and staging carry rate_limits policies that no migration
created (rate_limits_select_own_or_global, "Users can read own limits"),
both allowing global rows. Dropping by the migration's own name would
have left them. Drop every policy on the two tables, and revoke client
writes on rate_limits. Rehearsed on read-only dumps of both projects.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Author: Programcode

supabase/migrations/20261016120000_security_preship_hardening.sql

@@ -148,18 +148,34 @@ BEGIN
 END;
 $$;
 
+-- The hosted projects carry policies on these two tables that no migration
+-- created (for example "rate_limits_select_own_or_global" and "Users can read
+-- own limits", both allowing user_id IS NULL). Drop every policy on them,
+-- whatever its name, and recreate only the one intended below.
+DO $$
+DECLARE
+  v_policy record;
+BEGIN
+  FOR v_policy IN
+    SELECT policyname, tablename FROM pg_policies
+    WHERE schemaname = 'public' AND tablename IN ('global_prompts', 'rate_limits')
+  LOOP
+    EXECUTE format('DROP POLICY %I ON public.%I', v_policy.policyname, v_policy.tablename);
+  END LOOP;
+END;
+$$;
+
 -- Operator instructions are part of the live system prompt; only Edge
 -- Functions (service role) read or write them.
-DROP POLICY IF EXISTS "global_prompts_select_all" ON public.global_prompts;
 REVOKE ALL ON TABLE public.global_prompts FROM anon, authenticated;
 
 -- Global limits (user_id IS NULL) are server configuration. A signed-in user
 -- may still read limits set for their own account.
-DROP POLICY IF EXISTS "rate_limits_select_own" ON public.rate_limits;
 CREATE POLICY "rate_limits_select_own" ON public.rate_limits
   FOR SELECT TO authenticated
   USING (user_id = (SELECT auth.uid()));
 REVOKE ALL ON TABLE public.rate_limits FROM anon;
+REVOKE INSERT, UPDATE, DELETE ON TABLE public.rate_limits FROM authenticated;
 
 -- Admin reporting RPCs relied only on require_admin() inside them; one reads
 -- every user's email. The admin Edge Function calls them with the service role.