Default download smoke inspection handoff outdir

[1613358894]

Summary

• replace the download-smoke inspect handoff placeholder with a deterministic sibling inspection output directory
• keep prepare/execute no-download boundaries unchanged and avoid creating the inspection directory during prepare
• update focused tests and reference docs

Validation

• python -m pytest tests/test_cli_download_smoke.py -q --basetemp .pytest_tmp_download_smoke_inspection_outdir -p no:cacheprovider
• python -m pytest tests/test_docs_consistency.py tests/test_docs_hygiene_script.py -q --basetemp .pytest_tmp_download_smoke_inspection_outdir_docs -p no:cacheprovider
• python scripts/check_docs_hygiene.py
• python scripts/check_workspace_hygiene.py
• git diff --check
• no-download Clostridium handoff rerun against E:\scratch\clostridium_download\cache\ncbi\download_plan.tsv