Emphasize operative rules in summaries and audit quiz contrasts

[kentwelcome]

Summary

• Prefer the observed operative rule in the summary headline and main Before/After cards, including material timing, conditions, and gates, rather than only the downstream result.
• Preserve branch-local evidence, mixed primary-result context, and the distinction between stated plans and executed actions. No report schema or deterministic fallback changes.
• Require a prefreeze source-side contrast audit for human-evaluation questions and assess every question against saved trial evidence after submission. Preserve frozen keys, original scores, and weak or unchanged outcomes.
• Add a synthetic mixed-timing gallery case and rendered-card invariants; document the policy and its semantic limits.

Tracking: DRC-4802.

Evidence and limits

The approved local prototype compares two authored presentations of identical synthetic evidence using the existing renderer. Browser verification covered view switching, operative timing details, mixed counts, primary-result context, and a 390px layout. The prototype is not included in this PR.

No live trial or extraction models were rerun. Synthetic rendering checks demonstrate renderer support, not model adherence to the revised prompt. Private evaluation artifacts, submitted answers, and scores remain untouched.

Verification

• bash tests/hooks-test.sh — passed.
• python3 plugin/skills/behavior-diff/scripts/decisions.py --check — passed.
• bash tests/live-report-contract.sh — passed.
• bash tests/release-workflow-test.sh — passed.
• python3 tests/report-schema-test.py — passed during implementation.
• python3 tests/human-evaluation-workflow-test.py — 15 passed.
• python3 tests/human-evaluation-quiz-test.py — 13 passed.
• Repository-wide Docker shfmt and Ruff formatting checks — passed.
• git diff --check — passed.

Independent read-only review

• Standards reviewer: APPROVE, no material findings or decisions required.
• Specification reviewer: APPROVE, no material findings or decisions required.
• Both followed REVIEWER_GUIDELINES.md and reviewed the complete six-file change and relevant contracts. Neither ran model calls or modified files.