A bound chord used to be `preventDefault`ed before its handler ran, so the
canvas took every ⌘C and ⌘V whether or not the node clipboard would act —
which is what blocked copying selected text out of the chrome floating over
the canvas. A binding may now return `false` to decline the key; ⌘C does so
when there is a text selection or no node selected, ⌘V when nothing of ours
is stored.
stroblme
23a80db6bb