Backend:
- Add cpuUsage field to AgentInstanceResponse (-1 if unavailable)
- Add queryAgentCpuUsage() to AgentRegistrationController — queries
avg CPU per instance from agent_metrics over last 2 minutes
- Wire CPU into agent list response via withCpuUsage()
Frontend:
- Add cpuUsage to schema.d.ts
- Compute maxCpu per AppGroup (max across all instances)
- Show "X% cpu" on compact cards when available (hidden when -1)
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>