Phase 5 Stage D moves: align useLiveTransforms with the direct mesh.position delta

User reported the slab/fence mesh jittered/teleported continuously
while dragging (not on commit — during the drag). Root cause: the
move tool wrote TWO conflicting values per grid:move tick:

 1. `mesh.position.set(deltaX, 0, deltaZ)` — relative offset, direct
    Three.js mutation.
 2. `useLiveTransforms.set(id, { position: [originalCenter + deltaX,
    0, originalCenter + deltaZ], rotation: 0 })` — absolute world
    position of the translated polygon center.

`ParametricNodeRenderer` reads `useLiveTransforms` and binds it via
React: `<group position={liveTransform.position}>`. So every Zustand
notification re-rendered the renderer and reconciled the group's
position back to "originalCenter + delta" (the absolute), overriding
the "delta" the direct mutation had just written. The two systems
fought every frame → visible jitter.

Fix: `useLiveTransforms.position` now holds the SAME delta the direct
mutation uses (`[deltaX, 0, deltaZ]`). React reconciles to the same
value the direct mutation already set — no conflict.

The cursor sphere position stays as the translated polygon center
(it's tracked separately via React state, not `useLiveTransforms`).

Ceiling aligned for consistency, though CeilingRenderer doesn't read
`useLiveTransforms` so the value there has no rendering effect.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

packages/nodes/src/ceiling/move-tool.tsx

@@ -90,8 +90,12 @@ export const MoveCeilingTool: React.FC<{ node: CeilingNode }> = ({ node }) => {
     const applyPreview = (deltaX: number, deltaZ: number) => {
       deltaRef.current = [deltaX, deltaZ]
       setMeshOffset(ceilingId as AnyNodeId, deltaX, deltaZ, height)
+      // Aligned with slab/fence: the delta matches the direct mesh
+      // mutation. CeilingRenderer doesn't bind position via React, so
+      // this entry isn't consumed for rendering, but kept consistent
+      // in case other systems read it.
       useLiveTransforms.getState().set(ceilingId, {
-        position: [originalCenter[0] + deltaX, height, originalCenter[1] + deltaZ],
+        position: [deltaX, 0, deltaZ],
         rotation: 0,
       })
       setCursorLocalPos([originalCenter[0] + deltaX, height, originalCenter[1] + deltaZ])