Custom double-click behavior

Override the default double-click behavior by replacing the SelectTool's Idle state method at runtime.

---

This example shows how to customize the double-click behavior on canvas by overriding the SelectTool's Idle state's handleDoubleClickOnCanvas method from the onMount callback.

The example demonstrates runtime method replacement, which is a powerful technique for customizing built-in tool behavior without creating entirely new tools. In this simplified version, double-clicking on the canvas shows an alert instead of creating a text shape, demonstrating the basic pattern for method override.

This pattern is useful when you want to extend existing tool behavior, add conditional logic, or customize built-in interactions without forking the entire tool.