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-segment/roof-segment-renderer.tsx

@@ -0,0 +1,29 @@
+import { type RoofSegmentNode, useRegistry } from '@pascal-app/core'
+import { useRef } from 'react'
+import type * as THREE from 'three'
+import { useNodeEvents } from '../../../hooks/use-node-events'
+import useViewer from '../../../store/use-viewer'
+import { roofDebugMaterials, roofMaterials } from '../roof/roof-materials'
+
+export const RoofSegmentRenderer = ({ node }: { node: RoofSegmentNode }) => {
+  const ref = useRef<THREE.Mesh>(null!)
+
+  useRegistry(node.id, 'roof-segment', ref)
+
+  const handlers = useNodeEvents(node, 'roof-segment')
+  const debugColors = useViewer((s) => s.debugColors)
+
+  return (
+    <mesh
+      material={debugColors ? roofDebugMaterials : roofMaterials}
+      position={node.position}
+      ref={ref}
+      rotation-y={node.rotation}
+      visible={node.visible}
+      {...handlers}
+    >
+      {/* RoofSystem will replace this geometry in the next frame */}
+      <boxGeometry args={[0, 0, 0]} />
+    </mesh>
+  )
+}