Code review r1 was right that AC5's evidence was empty: the smoke never
forced a settled render during a gesture, so the settled copy of
`.hp-editor-only-layer` was empty at every point it looked, and
`groups() === 1` held whether the copy was hidden or not.
Measuring the case the reviewer named turned up more than a weak assertion.
Ownership of the layer alternates on its own — every settled render ends in
`updated()` → `_commitLiveEditor()`, which empties the live root — so a
settled render mid-gesture takes the guides back and draws them itself, from
the same live `_alignPoint`. That much needs no suppression. But the copy it
leaves behind stays in the settled scene, and the NEXT live paint adds a
second one: measured two `.alignline` on one alignment, the settled one a
grid step behind the marker. So the suppression stays, and now it stays with
a witness.
The smoke counts what is visible, not what is in the DOM: the hidden copy is
still a node, and counting nodes is how this check could have looked green
while showing the user two lines. Its device scenario now drives the whole
handover — force an unrelated settled render mid-drag (`_hdrH`, the same
header-height observer that masked the defect in the S2 measurements), assert
the render actually happened, that the layer went back to the settled scene
with the live point on it, and that one real move later the live painter owns
it again — exactly one visible guide at every step.
Mutant `live-editor-keeps-the-settled-guides-visible` puts the suppression
back under the plan branch, as it was before this issue, and the smoke goes
red on `nextMoveTakesTheLayerBack`.
Issue: #521
User-Visible: no
#451 moved every editor gesture onto the live painter, and the guides stayed
behind in the settled scene. While a gesture runs, the settled scene is not
re-rendered at all, so the guides did not follow the marker in the device
editor, the shape in the backdrop editor, or the cursor while a contour is
drawn in the plan editor. Measured with real pointer events on the demo stand
against `origin/dev`, after waiting for the editor chrome to settle: three
gestures, each exactly on another object's axis, 0 settled render cycles,
`.alignline` 0 and no `.alignguides` group in all three.
The report called it two breaks. It is one — the layer — plus one thing that
would have broken the repair: `_alignPoint` read `_pos`, which during a live
gesture answers from the snapshot of the last settled render. Over one drag:
live 254.17 → 220.83 while `_pos` stayed at 254.17, eight grid steps behind,
so a restored layer would have drawn the guide at the marker's old place.
The live template now paints the guides in all three modes (the device editor
had no template at all — `paintDevice` only moves the marker element), and
`_alignPoint` takes the live position. The settled copy of
`.hp-editor-only-layer` is made transparent for the duration of any editor
gesture, not only in plan mode: two guides, one of them stale, is what the
user would otherwise see when an unrelated settled render lands mid-gesture.
`_renderAlignGuides` on the card becomes soft — a gesture that starts while
the editor runtime is still loading must cost nothing, and an exception inside
a `requestAnimationFrame` paint would take the whole gesture with it.
The witness is rewritten around the defect that hid this for two stable
releases: the old smoke assigned `_deviceDrag`/`_decorDraft` wholesale, and an
assignment with `oldValue == null` does not route to the live path — it
verified a state a real gesture never reaches. Every scenario now drives real
`PointerEvent`s, waits for silence first (the `_hdrH` settling window right
after entering a mode hands out settled frames that make even the broken code
draw a guide), and asserts zero settled cycles during the movements plus
exactly one `.alignguides` group. #400's exclusion is checked without touching
the drag state: the dragged marker must simply be absent from the candidates.
On `origin/dev` the smoke fails on nine of its facts; a witness that stays
green before the fix was the actual bug here.
Mutants: `live-editor-devices-drops-align-guides`,
`live-editor-decor-drops-align-guides`, `live-editor-plan-drops-align-guides`,
`align-point-reads-frozen-snapshot` — one per AC, all guarded by the smoke.
`test/smoke-harness-contract.test.mjs` pins that the smoke cannot go back to
fabricating gesture state.
Issue: #521
User-Visible: yes
Claude