Round 2 verification audit for C072

Model: gpt-5

Claim: Histogram overlap gives a ~= 1e-3 probability of P(up,up) being mislabeled as P(up,down)+P(down,up) upon thresholding, which is corrected in real time.

Source alignment: source/supp_content.tex:137-137 (Supp. Mat. S5)

Prior official verdict: partial with failure_reason None.

Executable evidence: run.py. Sandbox rerun logs: run.log.

Independent audit: I scanned the copied script for imports/shared helper dependencies and reran it through the sandbox. The code is self-contained in this attempt directory and targets the claim strategy: Paper-reported thresholding-error probability; cross-check with the 62-photon/bright-ion Poissonian overlap.. I checked the relevant family model rather than relying only on exit status; the rerun is treated as one reproducibility input.

Decision: Round 2 verdict is partial with failure_reason None and limitations ['paper_text_only_reimplementation']. Notes: Paper: ~1e-3 probability P(uu) mislabeled as P(ud)+P(du) from histogram overlap of 1- vs 2-bright-ion distributions. Reconstructed with Poisson(mu1=62) and Poisson(mu2=124): optimal threshold T=89 gives P(2-bright as 1-bright)=5.9e-4 (and 1->2 = 5.0e-4); midpoint threshold T=93 gives 2.2e-3. Both are order-of-magnitude consistent with the stated ~1e-3. Reconstruction relies on an idealized Poisson model (paper uses the measured histogram incl. background/dark counts) -> partial.