Rjl493456442 proposes unified Ethereum performance metrics across all clients instantly

@rjl493456442 proposes standardized cross-client Ethereum performance metrics to compare implementations. Goal is to enable fair benchmarking, network health monitoring, and data-driven protocol research. The proposal includes 17 core metrics categorizing block execution lifecycle phases. EIP-7907 analysis demonstrates the importance of standardization, showing 8.5x increase in per-call overhead for large contracts with Geth metrics.