🔧 fix(convert): validate soffice binary name and prevent path traversal

from convert_lo.exceptions import SofficeNotFoundError

_VALID_BINARY_NAMES = {"soffice", "soffice.exe", "soffice.bin"}

def _is_valid_soffice(candidate: Path) -> bool:

    """Validate that a candidate path is a plausible soffice binary.

    Checks that the filename matches expected binary names and that no

    path traversal components (``..``) are present.

    """

    if candidate.name not in _VALID_BINARY_NAMES:

        return False

    return ".." not in candidate.parts

def find_soffice() -> Path:

    """Locate the LibreOffice soffice executable.

    env_path = os.getenv("LIBREOFFICE_PATH")

    if env_path:

        candidate = Path(env_path)

        if candidate.exists():

        if candidate.exists() and _is_valid_soffice(candidate):

            return candidate

    candidates: list[Path] = []