Split the monolithic AllSystemInfo handler into smaller, focused functions:
- Extract streamSystemInfo for channel consumption
- Add queueSystemInfo for safe non-blocking queue operations
- Create collectSystemInfoRound for parallel agent data collection
- Implement handleRoundResult for consistent round result processing
- Replace custom exponential backoff with cenkalti/backoff/v5 library
This improves code maintainability and separates concerns within the metrics API endpoint.