Round 2 verification audit for C027

Model: gpt-5

Claim: Fig. 3a: the steady-state error associated with each individual error channel of probability p.

Source alignment: source/main.tex:139-145 (Fig. 3a)

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: Reproduce the per-channel steady-state error bar chart and compare to the published Fig. 3a.. 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 ['visual_match_only', 'paper_text_only_reimplementation']. Notes: Reproduced per-channel steady-state error grid for the 16 M_{i,j} depolarising channels (map rho->(1-p)rho+p M rho M^dag once/cycle after drive A). Global errors (interior 3x3) ~0; local errors amplified: X_I/I_X~4.89, Y_I/I_Y~4.89, Z_I/I_Z~3.88 (round to 5,5,4 as in Fig 3a panel). Matches paper structure. Theory-reproducible plot; Tier-A visual match only -> caps at partial.