feat(hub): add network probe API, sync, result collection, and aggregation

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

internal/hub/systems/system.go

@@ -168,6 +168,9 @@ func (sys *System) update() error {
 		}
 	}
 
+	// Fetch and save network probe results
+	go sys.fetchAndSaveProbeResults()
+
 	return err
 }