The issue was that the metric-level system was sending individual
metric fragments (CPU load, temperature separately) instead of
complete System/Service messages that the dashboard expects.
Now aggregates individual metrics into complete messages:
- CPU load + temperature -> complete System message
- Memory + processes -> complete System message
- Service metrics remain as complete messages
This should resolve 'No data received' on srv01 while maintaining
the 5-second CPU metric update frequency.