Theta-spec harness agnostic config surface

Theta-spec provides a standardized, harness-agnostic configuration surface for Ethereum execution layer clients, allowing developers to define and validate node configurations independently of any specific client implementation. It is designed for client teams, DevOps engineers, and researchers who need a unified way to manage diverse client setups without duplicating configuration logic. This project is interesting because it reduces fragmentation and maintenance overhead across the Ethereum ecosystem, enabling more portable and testable configurations.