Fixed scripts/check-provenance.sh to properly validate PROVENANCE.md
against actual fixture files. The script was failing silently due to
subshell EXIT trap removing temp files before parent could read them,
and arithmetic expansion returning exit code 1 on zero value.
Changes:
- Replaced subshell pipes with process substitution
- Moved temp file cleanup to after reading
- Added validated variable initialization
- Added || true to prevent exit on zero arithmetic
All 200 classifier corpus fixtures have valid provenance entries
with matching SHA256 hashes. PROVENANCE.md already existed with
complete documentation.
Refs: pdftract-5z5d8
Co-Authored-By: Claude Code <noreply@anthropic.com>
