Step 2 of the layout plan is done in the experiment checkout, at 1512d84
and 23523ee. The handoff carries the commits and what is left; LAYOUT.md
carries the settled rule, which is now one coordinate unit with the frame
a length of it and both pins beside each other; the log carries what
implementing the plan corrected in it, including the four that would have
shipped as wrong layout and the two rig gaps that hid them.