Phase 5 Stage D: re-port curve + whole-item move tools 1:1 from legacy

Each tool is now a direct copy of the legacy implementation, relocated
under @pascal-app/nodes/<kind>/ and dispatched via the registry's
def.affordanceTools. No DragAction abstraction, no clever live-drag
exception, no novel snap pipeline — same code, same UX, same
performance, same history dance.

Ports:
- fence/curve-tool.tsx    (legacy CurveFenceTool, 1:1)
- fence/move-tool.tsx     (legacy MoveFenceTool, 1:1 — including
                           the mesh.position + useLiveTransforms
                           exception that the legacy uses for fence
                           specifically)
- wall/curve-tool.tsx     (legacy CurveWallTool, 1:1)
- slab/move-tool.tsx      (legacy MoveSlabTool, 1:1)
- ceiling/move-tool.tsx   (legacy MoveCeilingTool, 1:1 — preview
                           fill + outline overlay preserved)

Drops the obsolete DragAction-based action files
(packages/nodes/src/{fence,wall,slab,ceiling}/actions/{curve,move}.ts)
and their now-empty actions/ directories where applicable. Fence
keeps actions/move-endpoint.ts since that port works.

Editor public surface gains `getWallGridStep` + `snapScalarToGrid`
(transitional exports — Stage F moves them into @pascal-app/nodes).

ToolManager + MoveTool dispatch unchanged: the same legacy-fallback
branches now mount the registry component because the affordances are
declared, but the rendered behavior matches the legacy because the
implementations are copies.

Per-kind progress: fence D ✅ (curve / move-endpoint / move / placement
all kind-owned), slab D ✅, ceiling D ✅, wall D 🟡 (curve only,
endpoint/move/placement still legacy).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

packages/editor/src/index.tsx

@@ -24,7 +24,11 @@ export {
   getAngleToSegmentReference,
   getSegmentAngleReferenceAtPoint,
 } from './components/tools/shared/segment-angle'
-export { isWallLongEnough } from './components/tools/wall/wall-drafting'
+export {
+  getWallGridStep,
+  isWallLongEnough,
+  snapScalarToGrid,
+} from './components/tools/wall/wall-drafting'
 export { CameraActions as ViewerToolbarRight } from './components/ui/action-menu/camera-actions'
 export { ViewToggles as ViewerToolbarLeft } from './components/ui/action-menu/view-toggles'
 export { useCommandPalette } from './components/ui/command-palette'