multivon-eval 0.13.0 — generation toolkit

The generation toolkit (#13): five ways to generate eval data, two of them free. Every generator stamps provenance, routes through the dedupe gates, and reports its rejects.

Added

• mutate_cases — deterministic, zero-LLM robustness mutations (typo/whitespace/case noise, unicode confusables, punctuation strip, conservative negation flip). Each mutant records its transformation and expectation: invariant, or flip with the old label cleared rather than silently kept. Byte-deterministic per seed.
• cases_from_template — parametric grids over named axes; full product (capped 2000) or greedy pairwise covering array. Rows without an expected output are valid for judge evaluators; no label is invented.
• generate_contrast_pairs — a minimally-edited unfaithful twin per case, judge-verified to actually flip before acceptance; rejected twins counted. Twins share a pair_id for genuinely paired comparisons.
• Span-grounded doc-QA — generate_from_text/from_file record each case's source span (offsets + chunk hash); unanswerable_fraction generates refusal-bait questions whose expected behavior is refusal. Unlocatable spans recorded as None and counted.
• simulate --export-cases / results_to_cases — persona transcripts become conversation EvalCases; empty transcripts skipped and counted.
• CLI: multivon-eval generate gains --mutate, --template/--axes/--sample, --contrast/--no-verify, --unanswerable-fraction, --per-case, --seed.

Notes

• 73 new tests. Mutation batches dedupe on exact input identity rather than the Jaccard gate (mutants are near-duplicates by construction — the gate would reject the suite it exists to create).