Reproduce the format and JPEG ladder run

1. Place this bundle in an empty directory and extract it.
2. Rename ill-benchmark-package.json to package.json.
3. Run: npm install
4. Run: node generate-format-benchmark.cjs .
5. Run: node generate-jpeg-ladder-figure.cjs .

Expected tool versions are pinned in package.json and recorded in the README. Results can still vary on a different platform or native dependency build; retain hashes and compare the new CSV instead of assuming byte-for-byte identity.
