diff --git a/supabase/migrations/20251006_complete_monolithic_setup.sql b/supabase/migrations/20251006_complete_monolithic_setup.sql
index 8493d88d..085712b4 100644
--- a/supabase/migrations/20251006_complete_monolithic_setup.sql
+++ b/supabase/migrations/20251006_complete_monolithic_setup.sql
@@ -2505,5 +2505,29 @@ BEGIN
   END IF;
 END $$;
 
+-- ============================================================================
+-- PART 11: LEGACY CLEANUP (#49 / #170)
+-- ============================================================================
+-- Pre-#49 leftovers from an old conflicting `00000000000000_rls_foundation.sql`
+-- migration (since deleted): the legacy `profiles` / `audit_logs` tables and
+-- the old `handle_new_user()` signup trigger function that fed them (plus its
+-- `handle_updated_at()` helper + `profiles_updated_at` trigger). The canonical
+-- schema uses `user_profiles` / `auth_audit_logs` written by
+-- `create_user_profile()` (see PART 8 + the on_auth_user_created trigger).
+--
+-- A fresh install from this file never creates these objects, so this block is
+-- ONLY to converge existing databases (prod) with a clean install. Verified
+-- safe on prod 2026-07-04 by the schema-drift audit (#170): both tables held
+-- ZERO real-user rows (audit_logs = 8263 legacy `user.signup` events, all
+-- null/E2E; profiles = 16 E2E throwaways), no view/FK/canonical-function
+-- referenced them, and handle_new_user was orphaned (no trigger fired it).
+-- Dropping handle_new_user/handle_updated_at also clears their
+-- function_search_path_mutable security-advisor flags.
+DROP TRIGGER IF EXISTS profiles_updated_at ON public.profiles;
+DROP TABLE IF EXISTS public.audit_logs CASCADE;
+DROP TABLE IF EXISTS public.profiles CASCADE;
+DROP FUNCTION IF EXISTS public.handle_new_user() CASCADE;
+DROP FUNCTION IF EXISTS public.handle_updated_at() CASCADE;
+
 -- Commit the transaction - everything succeeded
 COMMIT;
diff --git a/supabase/migrations/999_drop_all_tables.sql b/supabase/migrations/999_drop_all_tables.sql
index c6a936ff..7c3a0ef1 100644
--- a/supabase/migrations/999_drop_all_tables.sql
+++ b/supabase/migrations/999_drop_all_tables.sql
@@ -56,6 +56,12 @@ DROP TABLE IF EXISTS user_connections CASCADE;
 DROP TABLE IF EXISTS auth_audit_logs CASCADE;
 DROP TABLE IF EXISTS user_profiles CASCADE;
 
+-- Pre-#49 legacy leftovers (#170) — no-ops on a clean DB, dropped here so a
+-- full teardown clears them too if run against an older database.
+DROP TRIGGER IF EXISTS profiles_updated_at ON public.profiles;
+DROP TABLE IF EXISTS audit_logs CASCADE;
+DROP TABLE IF EXISTS profiles CASCADE;
+
 -- Drop trigger on auth.users if exists
 DROP TRIGGER IF EXISTS on_auth_user_created ON auth.users;
 
@@ -70,6 +76,9 @@ DROP FUNCTION IF EXISTS check_rate_limit(TEXT, TEXT, INET) CASCADE;
 DROP FUNCTION IF EXISTS record_failed_attempt(TEXT, TEXT, INET) CASCADE;
 DROP FUNCTION IF EXISTS update_conversation_timestamp() CASCADE;
 DROP FUNCTION IF EXISTS assign_sequence_number() CASCADE;
+-- Pre-#49 legacy signup-trigger functions (#170)
+DROP FUNCTION IF EXISTS handle_new_user() CASCADE;
+DROP FUNCTION IF EXISTS handle_updated_at() CASCADE;
 
 -- =========================================
 -- CLEANUP COMPLETE