[Shuvam1024]

Renames the project from RAGBench to ragstat and adds a short results summary at the top of the README.

Rename

• Package ragbench/ moved to ragstat/ (history preserved), imports, __main__, and the console script ragstat.
• pyproject.toml name, scripts, packaging, coverage source, mypy config, and repository URLs; uv.lock regenerated.
• Dockerfile, CI workflow (--cov=ragstat, docker tag), BEIR User-Agent, temp-file prefix, docs, configs, and README.

Kept for compatibility

• Schema identifiers ragbench-stats-v1 and ragbench-judge-v1, and the judge tool name ragbench_judge, so saved reports keep loading.
• Every committed benchmark report is unchanged byte-for-byte. A test checks that saved reports recording ragbench still load and compare, and that new reports record ragstat.

Results at a glance

A new README section rendered from the committed reports by scripts/render_readme_tables.py, covered by the README drift test. No metric, threshold, or selection changed.