Fix PC-assisted Robot Hardware installation

[temiroff]

Outcome

PC-assisted managed devices now receive a pinned Robot Hardware source and aarch64/x86_64 Python dependency bundle from the editor computer. Install Hardware no longer requires the target device to reach GitHub or PyPI, and it reuses the managed Python 3.11 environment.

The installer also recognizes and cleans the incomplete blacknode-robot clone left by a failed download while refusing to touch unrelated directories.

Verification

• Built the real pinned aarch64 Hardware bundle on Windows (11.3 MB)
• python -m pytest tests/test_editor_devices.py -q — 142 passed
• $env:PYTHONPATH=(Join-Path (Get-Location) 'python'); python -m unittest discover -s tests — 566 passed, 8 skipped
• Embedded remote Python blocks compile
• Generated remote shell installer passes �ash -n
• git diff --check

Managed Runtime release decision

No Runtime release is required. This changes the editor-server SSH orchestration behind the existing Install Hardware action; it does not change the managed Runtime service, API, installer, supervision, or package-sync contract. The editor/core release delivers the fix.