feat: supabase schema migrations + kong gateway config

supabase/migrations/post-boot.sql

@@ -0,0 +1,8 @@
+-- ============================================================
+-- post-boot — runs after all migrations have been applied.
+-- Grants INSERT/UPDATE to authenticator on user-facing tables.
+-- (Run after 01-init.sql so tables exist.)
+-- ============================================================
+
+GRANT INSERT, UPDATE ON search_queries TO authenticator;
+GRANT INSERT, UPDATE ON notifications TO authenticator;