Round 2 verification audit for C048

Model: gpt-5

Claim: Fig. (lambda_const_vs_altern): comparison of lambda_max for constant versus alternating drive (C) as a function of branching angle gamma, using lambda_max = lambda_+^{1/2} for the alternating case.

Source alignment: source/supp_content.tex:49-54 (Fig. lambda_const_vs_altern)

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: Plot both lambda_max(gamma) curves and confirm they match the figure.. 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 lambda_max(gamma) for constant vs alternating drive (C) using lambda_max=lambda_+^{1/2} for the alternating case. Constant min 0.8770 at gamma=0.221 pi (1/7.62); alternating min 0.8813 at gamma=0.231 pi (1/7.92), matching paper optima. Closed-form lambda_+ matches numeric second_eigmag to 1.6e-15. Curves and y-range match paper. Theory-reproducible plot; Tier-A visual match only -> caps at partial.