sync: update core and viewer from monorepo (#143)

Major changes:
- Roof system rewrite with roof-segment support
- Scene store refactor
- Spatial grid improvements
- Item light system
- Post-processing and selection manager updates
- Perf monitor component

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

packages/viewer/src/components/renderers/roof/roof-renderer.tsx

@@ -1,28 +1,40 @@
 import { type RoofNode, useRegistry } from '@pascal-app/core'
 import { useRef } from 'react'
-import type { Mesh } from 'three'
+import type * as THREE from 'three'
 import { useNodeEvents } from '../../../hooks/use-node-events'
+import useViewer from '../../../store/use-viewer'
+import { NodeRenderer } from '../node-renderer'
+import { roofDebugMaterials, roofMaterials } from './roof-materials'
 
 export const RoofRenderer = ({ node }: { node: RoofNode }) => {
-  const ref = useRef<Mesh>(null!)
+  const ref = useRef<THREE.Group>(null!)
 
   useRegistry(node.id, 'roof', ref)
 
   const handlers = useNodeEvents(node, 'roof')
+  const debugColors = useViewer((s) => s.debugColors)
 
   return (
-    <mesh
-      castShadow
+    <group
       position={node.position}
-      receiveShadow
       ref={ref}
       rotation-y={node.rotation}
       visible={node.visible}
       {...handlers}
     >
-      {/* RoofSystem will replace this geometry in the next frame */}
-      <boxGeometry args={[0, 0, 0]} />
-      <meshStandardMaterial color="white" />
-    </mesh>
+      <mesh
+        castShadow
+        material={debugColors ? roofDebugMaterials : roofMaterials}
+        name="merged-roof"
+        receiveShadow
+      >
+        <boxGeometry args={[0, 0, 0]} />
+      </mesh>
+      <group name="segments-wrapper" visible={false}>
+        {(node.children ?? []).map((childId) => (
+          <NodeRenderer key={childId} nodeId={childId} />
+        ))}
+      </group>
+    </group>
   )
 }