- Use same approach as run_optimization.py with use_iteration_folders=True
- NXSolver.create_iteration_folder() handles proper file copying
- Read NX settings from atomizer_spec.json or optimization_config.json
- Extract Nastran version from NX install path
- Creates iter0 folder for baseline (consistent with optimization numbering)
This fixes the issue where manually copying files didn't preserve
NX file dependency chain (.sim -> .afm -> .fem -> _i.prt -> .prt)