DFA + residual-branch penalty test: seed=42, lam=0.1
  ep 0: ||h_L||=8.893e+00 ||g_2||=9.934e-04 acc=0.1152
  ep 1: ||h_L||=7.313e+02 ||g_2||=1.234e-05 eval_acc=0.3330 test_acc=0.3271
  ep 10: ||h_L||=7.442e+03 ||g_2||=2.212e-06 eval_acc=0.3467 test_acc=0.3403
  ep 20: ||h_L||=1.436e+04 ||g_2||=1.377e-06 eval_acc=0.3457 test_acc=0.3452
  ep 30: ||h_L||=2.044e+04 ||g_2||=1.075e-06 eval_acc=0.3457 test_acc=0.3440
  ep 40: ||h_L||=2.549e+04 ||g_2||=9.277e-07 eval_acc=0.3584 test_acc=0.3450