- Move test_*.py → tests/integration/ - Move probe_*.py, dump_*.py → helpers/ - Move PERFORMANCE_AUDIT.md → docs/ - Move single_shot_PYTORCH_REFERENCE.py → dsv4/reference/ - Fix 3 import references in test_layer_comparison, test_mhc_comparison, test_compressor_position_bias - Add helpers/import_closure.py (dead-code detection tool)