Routine CIOS agents on Sonnet 4 instead of Opus

Decision

Sentinel and Homeostasis switched to claude-sonnet-4-20250514. All other 10 agents remain on claude-opus-4-6.

Rationale

Sentinel runs health check checklists (docker ps, HTTP endpoints, disk space). Homeostasis runs cleanup checklists (log rotation, MCP parity, stale handoffs). Neither requires complex reasoning or decomposition. Sonnet 4 handles structured checklist execution well at ~60% lower cost per invocation.

Alternatives Rejected

Keep all agents on Opus (rejected: wasteful for checklist work). Switch all non-orchestrator agents to Sonnet (rejected: specialists like Analyst and Communicator need reasoning depth for quality output).

Outcome

Pending