v2.3.0 - CIFAR-10 validated, Adam m fix

Peanut v2.3 - CIFAR-10 validated, Adam m fix.

What changed from v2.2:

• Fixed silent third change: first step m was 0, now m = Adam m. First update same size, step 2 now remembers g1.
• MLP check: v2.3 mean 0.8611 vs v2.2 mean 0.8619, within noise. Fix preserves performance.

CIFAR-10, 50 epochs, TinyCNN, 3 seeds, Colab T4:

• LR 0.003: Peanut 0.7847 mean, AdamW 0.7813 mean
• LR 0.01: Peanut 0.6526 mean, AdamW 0.3396 mean, AdamW collapses, one seed 0.1000

Peanut now wins on 2 datasets: Fashion-MNIST and CIFAR-10.
Thanks to community for finding the m bug.