Supervisor replaces maxRounds as primary stop mechanism. Every N rounds
(configurable via supervisorInterval, default 3), the engine calls a
cheap LLM to evaluate thread progress and decide continue/stop.
- New engine/supervisor.ts: runSupervisor + parseSupervisorDecisionText
- Supervisor is opt-in: no models.supervisor configured = always continue
- WorkflowConfig gains supervisorInterval (default 3, 0 to disable)
- Engine calls supervisor after each supervisorInterval rounds
- 256 tests pass, 14 new tests for supervisor logic
Refs #110
xiaoju
014c442ed2