- Refactor examples/ctf-demo to satisfy the review_case.py contract:
split evidence/E-001-E-003.md into per-record E-001/E-002/E-003.md
with ### E-xxx headings and severity/status/repro_command fields
- Add evidence/checksec-output.txt artifact with matching content_hash so
--verify-hashes has a real object to verify
- Convert report.md finding/path sections to structured F-01/P-01 blocks
- New case-contract CI job runs review_case.py --verify-hashes --strict on
examples/ctf-demo; local result: PASS (0 errors, 0 warnings)