fix: clean up tmp_dll_path on integrity verification failure

[catalini82]

Summary

Fixes a temporary file leak in ensure_binary() when the Windows CUDA DLL archive path fails during download, integrity verification, size validation, or extraction.

The main archive temporary file (tmp_path) was already cleaned up in the exception handler. The separate Windows CUDA DLL archive temporary file (tmp_dll_path) was not, because it is also created with NamedTemporaryFile(delete=False) and needs explicit cleanup.

Changes

oprel/runtime/binaries/installer.py

• Adds tmp_dll_path cleanup in the except Exception as e: handler.

• Cleanup is guarded with:

  • "tmp_dll_path" in locals() so failures before DLL temp creation are safe.
  • tmp_dll_path.exists() so already-removed files do not cause errors.

• Existing tmp_path cleanup is preserved.

• Original exceptions remain chained through BinaryNotFoundError(... ) from e.

tests/unit/test_download_integrity.py

Adds coverage for:

• Main archive integrity failure cleans tmp_path.
• DLL archive integrity failure cleans tmp_dll_path.
• DLL archive size mismatch cleans tmp_dll_path.
• Success path with no manifest entry still cleans temporary archives normally.

The Windows CUDA tests monkeypatch get_binary_info() and resolve_version() so they do not depend on current registry constants. Fake downloads route by exact fake URL equality, with an assertion on unexpected URLs.

What did not change

• No public API changes.
• No registry URL changes.
• No manifest entries added.
• No real or fake checksums added.
• No config changes.
• No dependency changes.
• No success-path download or extraction behavior changes.
• No extracted directory cleanup added; this PR only handles temporary downloaded archive files.

Validation

• python3 -m py_compile oprel/runtime/binaries/installer.py
• python3 -m py_compile oprel/runtime/binaries/integrity.py
• python3 -m pytest tests/unit/test_download_integrity.py -q -o addopts="" → 33 passed
• python3 -m pytest tests/unit/test_integrity.py -q -o addopts="" → 33 passed
• PYTHONPATH=. python3 scripts/smoke_import.py → passed
• git diff --check → passed

Target branch: dev