fix(editor): harden editor interactions and WebGPU rendering

Fix editor bug sweep regressions, WebGPU CSG/material crashes, Shift snap bypass behavior, arrow handle drag projection, and the wall preview null guard covered by the Sentry follow-up PRs.

packages/nodes/src/shared/roof-wall-opening-cut.ts

@@ -1,26 +1,22 @@
-import type { RoofSegmentNode, RoofWallFaceId } from '@pascal-app/core'
+import type { DoorNode, RoofSegmentNode, WindowNode } from '@pascal-app/core'
 import { getRoofWallFaceFrame, roofFacePointToSegment } from '@pascal-app/core'
+import { buildOpeningCutoutGeometry, hasFlatOpeningCutoutBottom } from '@pascal-app/viewer'
 import * as THREE from 'three'
 
-type RoofWallOpening = {
-  roofSegmentId?: string
-  roofFace?: RoofWallFaceId
-  position: [number, number, number]
-  width: number
-  height: number
-}
-
 /**
  * CSG cut for a door / window hosted on a roof-segment wall face
- * (`capabilities.roofAccessory.buildCut`). A box through the wall
+ * (`capabilities.roofAccessory.buildCut`). The cut goes through the wall
  * mid-plane, derived from the CURRENT host geometry (the opening stores
  * face-local coords), so the hole follows segment resizes for free.
+ * Plain rectangles cut a box; shaped openings (arch / rounded /
+ * frameless `opening` kind) reuse the wall pipeline's cutout profile so
+ * roof-hosted holes match wall-hosted ones.
  *
  * Returns null for wall-hosted openings: their cut is handled by the
  * wall system's own cutout pipeline.
  */
 export function buildRoofWallOpeningCut(
-  node: RoofWallOpening,
+  node: DoorNode | WindowNode,
   hostSegment: RoofSegmentNode,
 ): THREE.BufferGeometry | null {
   if (!node.roofSegmentId || !node.roofFace) return null
@@ -32,8 +28,10 @@ export function buildRoofWallOpeningCut(
 
   // A door's cut bottom is coplanar with the wall brush base — extend it
   // slightly downward so three-bvh-csg never has to clip coplanar faces.
+  // Only a flat bottom chord may extend; a rounded bottom is never
+  // coplanar and shifting it would distort the profile.
   const bottom = node.position[1] - node.height / 2
-  const bottomPad = bottom < 0.005 ? 0.02 : 0
+  const bottomPad = bottom < 0.005 && hasFlatOpeningCutoutBottom(node) ? 0.02 : 0
 
   const center = roofFacePointToSegment(hostSegment, node.roofFace, [
     node.position[0],
@@ -42,9 +40,35 @@ export function buildRoofWallOpeningCut(
   ])
   const { yaw } = getRoofWallFaceFrame(hostSegment, node.roofFace)
 
-  const geo = new THREE.BoxGeometry(node.width, node.height + bottomPad, depth)
-  geo.translate(0, -bottomPad / 2, 0)
+  const geo = buildCutGeometry(node, wallThickness, depth, bottomPad)
   geo.rotateY(yaw)
   geo.translate(center[0], center[1], center[2])
   return geo
 }
+
+function buildCutGeometry(
+  node: DoorNode | WindowNode,
+  wallThickness: number,
+  depth: number,
+  bottomPad: number,
+): THREE.BufferGeometry {
+  const shaped =
+    node.openingKind === 'opening' ||
+    node.openingShape === 'arch' ||
+    node.openingShape === 'rounded'
+
+  if (!shaped) {
+    const geo = new THREE.BoxGeometry(node.width, node.height + bottomPad, depth)
+    geo.translate(0, -bottomPad / 2, 0)
+    return geo
+  }
+
+  const halfWidth = node.width / 2
+  const halfHeight = node.height / 2
+  return buildOpeningCutoutGeometry(
+    node,
+    { left: -halfWidth, right: halfWidth, bottom: -halfHeight - bottomPad, top: halfHeight },
+    depth,
+    wallThickness,
+  )
+}