Runs one trial and returns its raw output. The default (spawnAgent)
drives the real claude CLI; runEvalWith takes one explicitly, so the eval
orchestration is testable without a model (pass a fake returning canned
stream-json) and a custom runtime can be plugged in.
Runs one trial and returns its raw output. The default (
spawnAgent) drives the realclaudeCLI;runEvalWithtakes one explicitly, so the eval orchestration is testable without a model (pass a fake returning canned stream-json) and a custom runtime can be plugged in.