feat: add core identity schema

migrations/0002_core_identity.down.sql

@@ -0,0 +1,7 @@
+DROP INDEX IF EXISTS public.memberships_profile_id_idx;
+DROP INDEX IF EXISTS public.memberships_tenant_id_idx;
+DROP TABLE IF EXISTS public.memberships;
+DROP INDEX IF EXISTS public.tenants_slug_key;
+DROP TABLE IF EXISTS public.tenants;
+DROP TABLE IF EXISTS public.profiles;
+DROP TYPE IF EXISTS public.membership_role;