fixes from the fourth adversarial review

[mnkprs]

Why

A fourth adversarial review of the delivered v0.1.0 found seven issues: a repeat-run guard that only compared variants, a reproduction command downloading a moving dataset revision, headline numbers not labelled as development-set results, two narrative claims contradicted by the committed predictions, a report command that fails on a clean clone without saying how to fix it, a lay-out contract requiring a field the generated file omitted, and a wrong claim about which variants use calibration data. All seven were verified against the code and data before fixing.

What changed

• src/report.ts: --final-repeat now must match the final run's variant, model and case universe (n / flagged / usable), with a message naming every mismatch; both table titles carry "development set". src/report.test.ts adds a CLI-level rejection test (27 tests total). --markdown output re-verified byte-identical to README §4 after the title change.
• src/lib/audit.ts: the fail-closed workspace error now names the fix (npm run data:workspaces).
• src/show.ts: human-labels.md gains a difficulty row; examples/astropy__astropy-12544/ regenerated.
• README: the top result and both §4 headings are labelled as development-set numbers (no held-out evaluation), making the §6c claim that every headline figure carries this caveat true; §2d's baseline row and §6's challenging-case narrative now match the committed predictions (underspecified=1 came from v1, v2, v4 and the first v5 run; the repeats, v6 and v7 stayed at 2); §2c notes the report needs cloned workspaces.
• REPRODUCE.md: parquet download pinned to the CI revision e48e2bd1… with curl --fail; calibration attributed to the v4–v6 experiments, not the v3 default; §5 lists report.ts among the commands needing workspaces.
• skills/fairtask-eval/SKILL.md: same pinned parquet URL; the report row and the gotcha state the workspace prerequisite.
• trajectories/v3-verify/astropy__astropy-12544.md: committed the deterministic re-render (running the renderer no longer dirties the tree).