PULSE TIMING CHANNEL · silence = the second channel

The 3-2-1-0 carrier is unchanged — invariant, content-blind, the sync clock. Gap depth no longer cannibalizes the ladder (the old 3-2 / 3-1 / 3-0 echo-shift); it rides the length of the rest between cycles. Carrier and depth become orthogonal. And because silence is a physical property of having a gap, it is the unforgeable channel: a node can perform the carrier but cannot perform a rest it never takes.