fix stair building rotation

packages/editor/src/components/tools/roof/move-roof-tool.tsx

@@ -29,9 +29,13 @@ export const MoveRoofTool: React.FC<{
   const [cursorWorldPos, setCursorWorldPos] = useState<[number, number, number]>(() => {
     const obj = sceneRegistry.nodes.get(movingNode.id)
     if (obj) {
-      const pos = new THREE.Vector3()
-      obj.getWorldPosition(pos)
-      return [pos.x, pos.y, pos.z]
+      const worldPos = obj.getWorldPosition(new THREE.Vector3())
+      // Cursor renders inside the building-local ToolManager group, so convert
+      // world → building-local to honor any building rotation.
+      const buildingId = useViewer.getState().selection.buildingId
+      const buildingObj = buildingId ? sceneRegistry.nodes.get(buildingId as AnyNodeId) : null
+      if (buildingObj) buildingObj.worldToLocal(worldPos)
+      return [worldPos.x, worldPos.y, worldPos.z]
     }
     // Fallback if not registered (e.g. newly created duplicate without mesh yet)
     if (
@@ -114,10 +118,15 @@ export const MoveRoofTool: React.FC<{
       }
     }
 
-    const computeLocal = (gridX: number, gridZ: number, y: number): [number, number] => {
-      let localX = gridX
-      let localZ = gridZ
-
+    const computeLocal = (
+      gridX: number,
+      gridZ: number,
+      y: number,
+      buildingLocalX: number,
+      buildingLocalZ: number,
+    ): [number, number] => {
+      // Segments have a transformed parent (stair/roof). Convert world → parent-local
+      // via Three.js hierarchy so the segment's stored position stays parent-relative.
       if (
         (movingNode.type === 'roof-segment' || movingNode.type === 'stair-segment') &&
         movingNode.parentId
@@ -128,19 +137,21 @@ export const MoveRoofTool: React.FC<{
           if (parentObj) {
             const worldVec = new THREE.Vector3(gridX, y, gridZ)
             parentObj.worldToLocal(worldVec)
-            localX = worldVec.x
-            localZ = worldVec.z
-          } else {
+            return [worldVec.x, worldVec.z]
+          }
           const dx = gridX - (parentNode.position[0] as number)
           const dz = gridZ - (parentNode.position[2] as number)
           const angle = -(parentNode.rotation as number)
-            localX = dx * Math.cos(angle) - dz * Math.sin(angle)
-            localZ = dx * Math.sin(angle) + dz * Math.cos(angle)
-          }
+          return [
+            dx * Math.cos(angle) - dz * Math.sin(angle),
+            dx * Math.sin(angle) + dz * Math.cos(angle),
+          ]
         }
       }
 
-      return [localX, localZ]
+      // Stair/roof live directly in the level — their stored position is building-local.
+      // event.localPosition is already building-local, so using it handles building rotation.
+      return [buildingLocalX, buildingLocalZ]
     }
 
     const onGridMove = (event: GridEvent) => {
@@ -161,7 +172,7 @@ export const MoveRoofTool: React.FC<{
       const lz = Math.round(event.localPosition[2] * 2) / 2
       setCursorWorldPos([lx, event.localPosition[1], lz])
 
-      const [localX, localZ] = computeLocal(gridX, gridZ, y)
+      const [localX, localZ] = computeLocal(gridX, gridZ, y, lx, lz)
 
       // Directly update the Three.js mesh — no store update during drag
       const mesh = sceneRegistry.nodes.get(movingNode.id)
@@ -181,8 +192,10 @@ export const MoveRoofTool: React.FC<{
       const gridX = Math.round(event.position[0] * 2) / 2 // world, for computeLocal
       const gridZ = Math.round(event.position[2] * 2) / 2
       const y = event.position[1]
+      const lx = Math.round(event.localPosition[0] * 2) / 2
+      const lz = Math.round(event.localPosition[2] * 2) / 2
 
-      const [localX, localZ] = computeLocal(gridX, gridZ, y)
+      const [localX, localZ] = computeLocal(gridX, gridZ, y, lx, lz)
 
       wasCommitted = true