Interactive chooser/router: pauses execution, shows the image with up to
10 labeled route buttons + edit-mask + stop. Chosen route gets the image,
others ExecutionBlocker-ed; gate-painted mask on a fixed output; stop
raises InterruptProcessingException. TDD plan with a pure torch-free
gate_bus; lazy comfy imports keep node logic unit-testable.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
