fix: remove created_at from hierarchy_module export config

The created_at field was the only timestamptz column exported for any
module table. Since it uses DEFAULT now(), it caused non-deterministic
output in constructive-db's generate:constructive pipeline. No other
module exports created_at — removing it for consistency and to
eliminate the non-determinism source.

Author: pyramation

pgpm/core/src/export/export-meta.ts

@@ -671,8 +671,7 @@ const config: Record<string, TableConfig> = {
       rebuild_hierarchy_function: 'text',
       get_subordinates_function: 'text',
       get_managers_function: 'text',
-      is_manager_of_function: 'text',
-      created_at: 'timestamptz'
+      is_manager_of_function: 'text'
     }
   },
   membership_types_module: {