hitTest method
Performs hit testing at a point.
Tests in priority order: ports → nodes → connections → annotations → canvas
Implementation
HitTestResult hitTest(Offset point) {
// 1. Ports (highest priority)
final portResult = _hitTestPorts(point);
if (portResult != null) return portResult;
// 2. Nodes
final nodeResult = _hitTestNodes(point);
if (nodeResult != null) return nodeResult;
// 3. Connections
final connectionResult = _hitTestConnections(point);
if (connectionResult != null) return connectionResult;
// 4. Annotations
final annotationResult = _hitTestAnnotations(point);
if (annotationResult != null) return annotationResult;
// 5. Canvas (background)
return const HitTestResult(hitType: HitTarget.canvas);
}