- Remove redundant platform= test seam from _terminal_may_leak_cpr(); use monkeypatch.setattr(sys, 'platform', ...) consistently in both test files. - Wrap PTY tests in try/finally for fd cleanup on assertion failure. - Guard select.select() in terminal thread against OSError after fd close (fixes PytestUnhandledThreadExceptionWarning). - Trim PR-number reference from test module docstring.