import os

def resolve_with_base_env(path: str, env_name: str) -> str:
    """
    If `env_name` is set and `path` is NOT absolute, NOT a URL/scheme,
    and does not already exist locally, prepend the `env_name` directory.

    If the resulting path does not exist, return the base environment directory instead.
    Otherwise return `path` unchanged.
    """
    base = os.getenv(env_name, "").strip()
    if not base:
        return path
    if os.path.isabs(path):
        return path
    if os.path.exists(path):
        return path

    candidate = os.path.join(base.rstrip("/"), path.lstrip("/"))
    if os.path.exists(candidate):
        return candidate
    else:
        raise FileNotFoundError