Method onModelsChange

app/src/utils/ModelManager.ts:716–721

* Subscribe to model list changes

(listener: (models: Model[]) => void)

   * Subscribe to model list changes
   */
  public onModelsChange(listener: (models: Model[]) => void): () => void {
    this.listeners.push(listener);
    return () => {
      this.listeners = this.listeners.filter(l => l !== listener);
    };
  }

  private notifyListeners(): void {
    const models = this.listModels().models;