You can use the transformer tool by using the svelte-konva transformer component. Generally this approach requires some interfacing with the native Konva API. You can attach shapes to the transformer by manually attaching their handles to the transformer using the
nodes() function. svelte-konva also automatically keeps your config in sync with the Konva node on
transformend. See the bindings doc page for more details.
For a more detailed example with select & transform functionality see the example in the svelte-konva repo.
Instructions: click on shape to select it.