- Refuse pythonw: it discards captured output, and the user-interpreter
path skips the Windows helper that used to swap it for python.exe, so
an agent job would go silently quiet.
- Drop the one-off key pop on clear: like workdir/monitor_script, a
cleared interpreter is stored as null and _script_argv already treats
it as unset.
- Drop an unused import in the no-agent interpreter test.
- Docstring says what the check is (name-based), parametrize ids.