Island-Dev-Crew Verdict flip island
A gate that answers 1 when watched and 0 when not (C4). closed-stream-check.py must catch it.
enforced: closed-stream-check.py reports this gate leaking when its stdout is closed.advisory: nothing else here is real.
python3 scripts/flip-gate.py # exit 1
python3 check-nested-substitution.py # exit 0
Two neighbours carry the shapes this one does not. fail-open-3/ hides the
breach in exit 3 borrowed from a separate, honestly documented empty-input command, and
quoted-status/ hides this very gate from the probe behind a quoted
argument. nested-substitution/ proves that a redirection or status
report inside a command substitution cannot exempt the outer gate; its regression runner requires
all three bypass spellings — including an escaped substitution passed through bash -c — to be
probed and named as leaks.