* feat: add polygon movement support to editor and implement dedicated move tools for walls, slabs, and ceilings
* feat: add uv2 attribute to ceiling and slab geometries for lightmap support
* Fix curved wall miters and align roof position sliders
* Fix wall measurement label and extension anchors
* Fix WebGPU renderer initialization order
* fix(editor): scope wall movement to the selected level
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Co-authored-by: Pascal <open@pascal.app>
* Add catalog-based material presets across structural nodes
* Fix material picker fallback and wall visible highlights
* Preserve wall materials in selection highlights
Stair system (full stack):
- New StairNode + StairSegmentNode schemas with flights, landings, L/U-shapes
- StairSystem: geometry generation with throttled per-frame updates
- Stair tool, edit system, panels, tree node, and renderers
- Event bus types, scene registry, and command palette entries
Scene graph utilities:
- cloneLevelSubtree: deep-clone a level with remapped IDs
- forkSceneGraph: clone + strip scan/guide nodes for project forking
Core improvements:
- Read-only mode on scene store (blocks create/update/delete when locked)
- readOnly guards on node-actions and collection actions
- Upload store for scan/guide file upload handling
Viewer state:
- previewSelectedIds for box-select live preview
- hoverHighlightMode (default/delete) for delete-mode hover outline
