fix(a11y): keep menu arrow keys from dragging the node underneath (#14543)

Menus rendered inline rather than in a portal live inside React Flow's node
element, which listens for arrow and selection keys on that element itself.
Radix consumes those keys for its own roving focus but lets them keep
bubbling, so one arrow press both navigates the menu and moves the node.

Stop the keys React Flow reserves at the content element, at the two shared
primitives instead of the ten call sites that use them.