A frame that changed nothing is no longer read as a lost one

Every frame an owner sends carries the version of the frame it sent before, and a mirror that receives a frame chained onto a version it never applied knows a frame was lost and asks for a fresh snapshot. That detector is right to exist — a lost frame used to be a silent, permanent deficit.

It had one blind spot. A mirror that received a patch which changed nothing — a layout area re-rendered with an identical control, a value written back as it was — skipped it without emitting anything, and also without moving its clock. The owner had chained the next frame onto that skipped one, so the next frame looked like proof of a loss that never happened, and the mirror re-asked for a snapshot it already held.

Measured on an Education gate run: 164 Frame loss detected warnings in one thirty-minute run, and 164 of them preceded by exactly this skip of the frame the next patch chained onto. Not one was a real loss. The cost was a round trip per page load and a warning that pointed everyone at the wrong subsystem for two nights.

A skipped no-op frame now adopts its version silently — no emission, no consumer sees a change, only the clock moves — so the chain stays intact and the detector fires only on what it was built for.