Add coverage for objective_integrity kind_recall non-dict and out-of-range guards

[galuis116]

benchmark/objective_integrity._kind_recall_problems has two guard branches that are never exercised by the test suite:

• line 188 — if not isinstance(objective, dict): return ["objective is not a dict"]
• line 195 — if not _is_ratio(value): return [f"kind_recall={value!r} is not a ratio in [0, 1]"]

test_kind_recall_problems_helper covers the empty and bool-kind_recall cases, but not these two — even though the sibling helper's test, test_recall_field_problems_helper, already covers the same non-dict and out-of-range branches for _recall_field_problems.

Ask

Add the two missing assertions to test_kind_recall_problems_helper (a non-dict objective and an out-of-range kind_recall), mirroring the sibling helper's coverage. Tests only.

[vanguarstew]

This fits the current roadmap focus on benchmark correctness and hardening — it adds missing coverage for two guard branches in objective_integrity._kind_recall_problems, mirroring the sibling helper's tests. Tests-only, no behavior change, so no perf:* label is warranted. Please add the two assertions to test_kind_recall_problems_helper and ensure the suite passes with VANGUARSTEW_OFFLINE=1 python -m pytest -q --cov=agent --cov=benchmark --cov-fail-under=75. Next step: implement and open the PR referencing this issue.