## Summary
- remove unsupported `node-pty` artifacts before Windows signing runs,
including Darwin prebuild directories and the extra `bin` directory
- keep the supported Windows `node-pty` runtime binaries in place for
packaged app execution
- expand the Windows signing unit test to verify unsupported artifacts
are removed and Windows binaries remain

## Test plan
- npm run fmt
- npm run lint:fix
- npm run ts
- npm test

#skip-bugbot

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