_raise_stat_error() maps the message of a failed remote stat to an
exception. A stat below a file answers "not a directory", which falls
through to the generic EIO: the path is simply absent, and callers see a
re-raised error instead of the FileNotFoundError the "no such file" branch
already gives. Map it to FileNotFoundError, so existence checks see
absence.
Assisted-by: unsloth/Qwen3.8-27B-GGUF:Q4_K_M with pi.dev v0.99.2
Signed-off-by: Jan Lindemann <jan@janware.com>