LoadTypes() declares mod_names as Iterable[str], so passing a single
module name as a bare string is not caught at call time and the string
is iterated character by character at load time, producing a
ModuleNotFoundError for the first character instead of a clear error.
Normalize a bare string to a one-element list in __init__() and widen
the annotation accordingly, so that both forms work.
Assisted-by: unsloth/Qwen3.8-27B-GGUF:Q4_K_M with pi.dev v0.84.2
Signed-off-by: Jan Lindemann <jan@janware.com>