Ethereum's Devnet-3 Launches Interoperability Testing with Key Updates Deployed

Ethereum's Devnet-3 is live with Zeam and Lantern ready for interop testing. Recursive aggregation API complete by Emil with simplified approach, no Merkle tree of public keys needed. Fixed-size SSZ Signature Container implemented in leanSpec after discussion. Long-running Devnet-2 nears 24 hours of finalization with multiple fixes landed. Client onboarding: Zeam and Ream ready for interop, Gean integrating leanQuickStart for multi-client testing.