```python
# Hypothesis: a few components amplify repeated reasoning; attribute growth of the repetition contrast using recorded activations, then ablate the strongest MLP writer.
meta4=json.load(open("/work/fwd_4/meta.json"))
print("Metadata keys:", list(meta4))
lens4=[124,123,131,136,107,146,98,135]
M4={l:np.load(f"/work/fwd_4/mlp_act_{l}.npy").astype(np.float32) for l in range(24)}
H4={l:np.load(f"/work/fwd_4/hidden_{l}.npy").astype(np.float32) for l in range(25)}
meansM={l:np.stack([a[i,lens4[i]-36:lens4[i]].mean(0) for i in range(8)]) for l,a in M4.items()}
meansH={l:np.stack([a[i,lens4[i]-36:lens4[i]].mean(0) for i in range(8)]) for l,a in H4.items()}
diffH={l:(a[1::2]-a[::2]).mean(0) for l,a in meansH.items()}
candidates4=[]
for l in range(24):
    d=torch.from_numpy(diffH[min(l+1,23)]);d=d/d.norm()
    writes=(d@downweights[l]).numpy()
    dm=meansM[l][1::2]-meansM[l][::2]
    scores=dm*writes
    avg=scores.mean(0)
    for j in np.argsort(avg)[-5:]:
        candidates4.append((round(float(avg[j]),5),l,int(j),int((scores[:,j]>0).sum()),round(float(dm[:,j].mean()),4)))
    if l<23:
        dh=diffH[l+1]-diffH[l]
        mwrite=downweights[l].numpy()@dm.mean(0)
        print("Layer",l,"contrast norm",round(float(np.linalg.norm(diffH[l+1])),3),"block growth",round(float(dh@d.numpy()),4),"MLP",round(float(mwrite@d.numpy()),4),"attention",round(float((dh-mwrite)@d.numpy()),4))
print("Top MLP writers:", sorted(candidates4,reverse=True)[:20])
# A one-neuron intervention is a causal probe, not yet a retained edit.
target19="model.language_model.layers.19.mlp.down_proj.weight"
w=downweights[19].clone()
w[:,11]=0
save_edit(target19,w)
print("Probe: layer 19, MLP neuron 11 output ablated; relative tensor change",float((w-downweights[19]).norm()/downweights[19].norm()))
with open("/work/notes.md","a") as f:
    f.write("Pass 2 TF paired productive vs repetition examples showed a common repetition direction (cosine ~0.7 with generation contrast), but chat template adds an empty think block. Corrected in pass 3 (files fwd_4) using raw template. Testing layer19 MLP neuron11 output ablation; strongest matched-context repetition writer. Attention-return request failed and did not count.\n")
```