- DEFAULT_CONFIG defines output_format, output_quality, output_dir,
last_garment_dir, last_print_dir
- load_config(): merges file values with defaults; never raises on
missing, damaged, or non-object JSON root
- save_config(): creates config/ dir as needed; logs error on failure
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>