[irl-dan]

Sharp marginal calibration bounds do not establish that every combination of parameter values is jointly feasible. At the shortest spacing, a=0.04004 and b=0.382 each attain an admissible marginal maximum, yet together exceed the original q2 upper bound by 0.00008. Native observations of those two scalar values also come from different cases.

Add this distinction to the existing calibration-stability reporting requirements, one contradictory producer claim, the authored reference and one interpretation case. The reference remains 682 words. No new reusable definition or runtime mechanism is needed; the example uses the same calibration and sensitivity contracts.

All 35 offline source commands pass, including twenty inherited tests. Exact arithmetic checks all sixteen marginal-rectangle corners (eight feasible, eight infeasible) and four combinations of retained native values. All 451 other original files and 32 package files are unchanged. The raw numerical observations, calculation source and plan are preserved; no native solver, financial model or provider call occurred.

This is a mathematical/reporting counterexample, not an observed agent failure or a claim that intentionally separate candidates must share bindings. Reporting and assessment remain agent-unqualified. Draft stacked on #40; no merge or publication requested.