syncSelection method
Synchronize selection state without firing user tap callbacks.
Use this from controller bridges/sync groups when another chart is the interaction source. The onSelectionChanged stream and listeners still receive the state change.
Implementation
void syncSelection(ChartSelection? selection) {
if (_disposed) return;
final nextSelection = selection?.snapshot();
if (_selection == nextSelection) return;
_selection = nextSelection;
_emitSelection(nextSelection);
_notifyIfAlive();
}