sync: comprehensive monorepo → editor parity (2D/3D decoupling, UX polish, crash fixes)

Squash merge of 3 commits:
1. useLiveTransforms store for 2D/3D decoupling + floorplan overhaul + Sentry crash fixes
2. Comprehensive 59-file sync bringing editor to full monorepo parity (selection highlights, delete tool, furnish/zone modes, keyboard shortcuts, all panels)
3. Missing files fix (materials.ts, merged-outline-node.ts, type fix)

75 files changed, ~6K additions.

packages/core/src/materials.ts

@@ -0,0 +1,24 @@
+import { DoubleSide, MeshStandardNodeMaterial } from 'three/webgpu'
+
+/**
+ * Shared base material for structural elements: walls, frames, slabs, roof.
+ */
+export const baseMaterial = new MeshStandardNodeMaterial({
+  color: '#f2f0ed',
+  roughness: 0.5,
+  metalness: 0,
+})
+
+/**
+ * Shared glass material for windows, glazed door panels, and glass items.
+ */
+export const glassMaterial = new MeshStandardNodeMaterial({
+  name: 'glass',
+  color: 'lightblue',
+  roughness: 0.05,
+  metalness: 0.1,
+  transparent: true,
+  opacity: 0.35,
+  side: DoubleSide,
+  depthWrite: false,
+})