- Move URL model-file validation logic to type_utils.looks_like_model_file and use it from __init__.py, civarchive
- Extract remote file-size probing into type_utils.fetch_remote_file_size and replace duplicated HEAD+Range logic in civarchive and huggingface
- Extract image normalization into type_utils.normalize_model_image, replacing duplicated CivitAI/CivArchive image mapping in civarchive and civitai
- Drop redundant local wrapper functions (_as_dict, _as_list, _version_sort_key, _select_primary_model_file, _extract_primary_file, _read_json_file, _write_json_file_atomic, _get_sha256_hash, _extract_civitai_image_id, _build_civitai_image_url) in favor of existing shared implementations
- Use path_utils.read_json_safe and write_json_atomic directly in model_list