SER-19 operator nodes

<!-- This is an auto-generated comment: release notes by coderabbit.ai --> ## Summary by CodeRabbit * **New Features** * On-chain node management: operators can register/manage nodes, declare supported models, and allocate/release compute capacity (FUCUs); task manager can query/select available operators. * **Improvements** * Tasks now reserve/release operator capacity automatically; operator selection considers available capacity. * Clients use validated typed configs, structured logging, unified transaction execution, and configurable gas strategies. * **Chores** * Updated ABIs, deployment wiring, configs, Python runtime pin, and CLI logging; removed legacy console/delegate utilities. * **Tests** * Added mocks and comprehensive tests for node lifecycle, model support, and FUCUs allocation. <!-- end of auto-generated comment: release notes by coderabbit.ai -->