feat: face-frame hosting for roof wall children + items on roof walls

Wall-mounted items join doors/windows on roof-segment wall faces, and
the storage model moves to FACE-LOCAL coordinates so hosted children
track segment edits live.

- Children store roofFace + position [u, v, z-from-mid-plane] with
  rotation 0 in-frame — the exact wall-child conventions (the wall
  volume's mid-plane lands on the nominal footprint). A shared
  <RoofFaceHostFrame> derives segment pose + face frame from the
  live-override-merged segment: children follow resize handle drags in
  real time and never jump on commit. No re-anchor cascade needed —
  position is authoritative, the frame is derived. migrateNodes
  converts branch-era segment-local data.
- Items: roofWallStrategy + roof:* handlers in the placement
  coordinator (surface 'roof-wall'), Shift free-place normalized with
  walls, ItemSystem wall-side push extended to segment hosts, correct
  2D plan glyphs via face→segment→roof pose composition. The roof
  hit resolver + overlap guard moved to @pascal-app/editor (the
  coordinator lives there; nodes already depends on editor).
- Cuts: subtractAccessoryCuts extracted and applied in BOTH the
  merged-shell and per-segment CSG paths (full edit mode / painted
  segments used to lose every hole), built from the CURRENT host
  geometry and live-effective children so holes follow segment and
  opening drags.
- Handle rig: the grandparent portal now maps the node's world pose
  into the portal frame instead of composing parent+node registry
  poses — correct for any nesting (the face-frame group broke the
  old assumption), identical for walls.
- Host-field hygiene: useDraftNode.commit/adopt and the window panel
  duplicate forward roofSegmentId/roofFace/wallId; every roof↔wall
  re-anchor clears and every revert restores them.

Codex-reviewed (design consultation, adversarial rounds on the
replaced cascade and on this refactor); frame conventions locked by
unit tests. Record: private-editor plans/editor-roof-wall-openings.md.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

packages/nodes/src/item/floorplan.ts

@@ -4,8 +4,11 @@ import {
   type FloorplanGeometry,
   type FloorplanPoint,
   type GeometryContext,
+  getRoofWallFaceFrame,
   getScaledDimensions,
   type ItemNode,
+  type RoofSegmentNode,
+  roofFacePointToSegment,
   useLiveTransforms,
 } from '@pascal-app/core'
 
@@ -112,6 +115,31 @@ function resolveItemTransform(
       y: shelfZ + offsetY,
       rotation: shelfRotationY + localRotation,
     }
+  } else if (parentNode?.type === 'roof-segment') {
+    // Roof-hosted wall item: FACE-LOCAL position mapped through the face
+    // frame, then composed through the segment's and parent roof's poses
+    // into level-local plan coords.
+    const segment = parentNode as RoofSegmentNode
+    const roof = segment.parentId
+      ? (ctx.resolve(segment.parentId as AnyNodeId) as
+          | (AnyNode & { position: [number, number, number]; rotation: number })
+          | undefined)
+      : undefined
+    if (roof?.type === 'roof' && item.roofFace) {
+      const frame = getRoofWallFaceFrame(segment, item.roofFace)
+      const segLocal = roofFacePointToSegment(segment, item.roofFace, item.position)
+      const [sx, sz] = rotateVec(segLocal[0], segLocal[2], segment.rotation ?? 0)
+      const [rx, rz] = rotateVec(
+        sx + segment.position[0],
+        sz + segment.position[2],
+        roof.rotation ?? 0,
+      )
+      result = {
+        x: rx + roof.position[0],
+        y: rz + roof.position[2],
+        rotation: (roof.rotation ?? 0) + (segment.rotation ?? 0) + frame.yaw + localRotation,
+      }
+    }
   } else {
     // Level / slab / ceiling parent — item.position is level-local.
     result = {