99f40c2488
CI / check (pull_request) Successful in 2m28s
- Add Usage type to protocol (turns, inputTokens, outputTokens, duration) - Add usage to StepRecord, StepNodePayload, StepEntry, STEP_NODE_SCHEMA - Thread usage through util-agent extract pipeline (writeStepNode → persistStep → createAgent) - All adapters return usage: null as placeholder (mock, hermes, claude-code, builtin) - 746 tests pass, no breaking changes (usage not in schema required array) Fixes #74 Refs #68