- useHeartbeatStatus reads from agent metadata (single source of
truth) instead of separate endpoint (eliminated split-brain).
- Online/offline threshold fixed to 10min to match server (was 15min).
- Dashboard polling lowered from 30s to 15s.
- Toggle feedback: invalidate agent queries immediately, clear
loading state after 2s.
- Removed command-table fallback from GetHeartbeatStatus endpoint,
dead helper functions, and unused GetRecentHeartbeatCommands.
14cd0884b4