Add task-adaptive review obligations and token traces

[areshand]

Summary

• derive durable review obligations from the candidate artifact and repair iteration
• let the orchestrator add monotonic risk-triggered reviews without allowing obligations to be waived
• block completion until all applicable reviews have passing artifact-bound evidence
• emit provider-neutral token usage summaries with every agent trace
• document task-adaptive role routing and deployment-owned pricing

Testing

• Not run (not requested)