op-geth was stuck at genesis (block 0, 0 L2 peers for 31h) because execution-layer
snap-sync had no peers. node_sync=true -> OP_NODE_SYNCMODE=consensus-layer (derive
L2 from L1) + geth --syncmode=full. Diagnosed by cursor on de-13.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>