engine/UPSTREAM_NOTE.md

# Suggested upstream change (NOT applied — shipped engine is verbatim)

The attestation covers file digests, so verification should be OS-agnostic.
Today `verify_attestation.py` exits 2 ("not a Surgeon package") on archives
re-zipped by Windows Explorer / PowerShell Compress-Archive (backslash entry
names) and by macOS Finder (`__MACOSX/` twins + `.DS_Store` break single-root
detection). This Space repairs the container in its wrapper before invoking
the engine, but local `python verify_attestation.py package.zip` still fails
on such archives.

Minimal engine-side fix (route through Michael):

1. normalize names once:  `names = [n.replace("\\", "/") for n in z.namelist()]`
   and read via a map from normalized -> original name;
2. ignore archiver junk when detecting the wrapper root and when reading:
   any path whose first segment is `__MACOSX`, or whose leaf is `.DS_Store`,
   `Thumbs.db`, `desktop.ini`, or starts with `._`.

Digest comparison logic unchanged; junk entries are never subjects.