The SkillTreeViewModel class serves as the view model for the skill tree and extends Flutter's ChangeNotifier for state management.
Features include:
- Storing and managing the list of SkillTreeNodes and SkillTreeEdges.
- Managing the state of the selected node.
- Initializing the skill tree with predefined nodes and edges.
- Methods for toggling node selection, allowing for only a single node to be selected at any given time.
The view model utilizes the GraphView package for visualization and layout.
