Provided by <SceneCanvas> / <StandardActionsRegistrar>. The extras
carry the active tool's kind + per-kind geometry. Callers
that need typed data must supply a richer insert dep.
Materialise a new node from the given drag-rect bounds and typed
per-kind extras. Returns the new node's id, or null if the consumer
rejected the insert (e.g. sub-threshold bounds, unknown kind).
Adapter dep for
insertAction.Provided by
<SceneCanvas>/<StandardActionsRegistrar>. Theextrascarry the active tool's kind + per-kind geometry. Callers that need typed data must supply a richerinsertdep.