Round 2 verification audit for C047

Model: gpt-5

Claim: Fig. (convergence): the singlet error after 50 cycles versus protocol parameters, with convergence slow-down near Phi=m pi/2, gamma=m pi/2, and theta=m pi (population trapping).

Source alignment: source/supp_content.tex:37-41 (Fig. convergence)

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: Simulate 50 cycles from |down,down> and reproduce the error-vs-parameter curves and the slow-down features.. 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: Simulated 50 cycles from |down,down> with the self-contained model and reproduced singlet error vs Phi, gamma, theta (panel a) and vs theta for 15/40/65 cycles (panel b). Reproduced slow-down features: error->1 at Phi=pi/2 and gamma=pi/2 (90 deg) and high error at theta=0/pi endpoints (m pi population trapping); theta minimum near 3pi/4. Matches paper qualitatively. Theory-reproducible plot; Tier-A visual match only -> caps at partial.