_is_interpreter_token matched Path(token).name against the bare-name regex, so a Windows venv path `...\Scripts\python.exe` (and the `py` launcher) recorded no ad-hoc evidence and the nudge loop the PR closes stayed open on that platform. Strip a case-insensitive .exe/.bat/.cmd suffix, take the basename across backslashes, and accept `py`. Parametrized invariant test, red before.