```python
def unpack_crates(crate: list) -> list:
    """
    Unpacks all items from nested crates into a flat list.

    :param crate: A list of strings or lists representing nested crates.
    :return: A list containing all item names in the order they appear.
    """
    result = []
    for item in crate:
        if isinstance(item, str) and item:
            result.append(item)
        elif isinstance(item, list):
            result.extend(unpack_crates(item))
        else:
            raise ValueError("Invalid entry: must be a non-empty string or a list.")
    return result

def crate_depth(crate: list) -> int:
    """
    Calculates the deepest nesting level of a nested crate.

    :param crate: A list of strings or lists representing nested crates.
    :return: The depth of the crate, where 1 is for no nesting and higher values indicate deeper levels.
    """
    if not crate:
        return 0
    max_depth = 0
    for item in crate:
        if isinstance(item, list):
            depth = crate_depth(item)
            if depth > max_depth:
                max_depth = depth
    return max_depth + 1
```