Phase 5 Stage D slab: port placement + move + boundary/hole editors

Replicates the fence Stage D recipe for slab — three drag affordances
+ one placement tool, all routed through the registry:

  affordanceTools:
    'boundary-edit' → thin <PolygonEditor> wrapper (vertex/edge drag)
    'hole-edit'     → same for a single hole polygon
    move            → DragAction with single-undo dance
  tool: () => placement (multi-click polygon with axis/45° snap)

`PolygonEditor` + `PolygonEditorProps` exported from
`@pascal-app/editor` as Stage D transitional surface (Stage F cleanup
moves them into `@pascal-app/nodes`).

ToolManager mount sites for SlabBoundaryEditor / SlabHoleEditor now
route through `getRegistryAffordanceTool` with legacy fallback.

Slab move action does not use the live-drag exception (polygon CSG
rebuild every tick) — matches legacy behavior; optimization is a
separate task once we measure.

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

packages/editor/src/components/tools/tool-manager.tsx

@@ -179,10 +179,31 @@ export const ToolManager: React.FC = () => {
         rotation={buildingRotation as [number, number, number]}
       >
         {showZoneBoundaryEditor && selectedZoneId && <ZoneBoundaryEditor zoneId={selectedZoneId} />}
-        {showSlabBoundaryEditor && selectedSlabId && <SlabBoundaryEditor slabId={selectedSlabId} />}
-        {showSlabHoleEditor && selectedSlabId && editingHole && (
-          <SlabHoleEditor holeIndex={editingHole.holeIndex} slabId={selectedSlabId} />
-        )}
+        {showSlabBoundaryEditor &&
+          selectedSlabId &&
+          (() => {
+            const Registry = getRegistryAffordanceTool('slab', 'boundary-edit')
+            return Registry ? (
+              <Suspense fallback={null}>
+                <Registry slabId={selectedSlabId} />
+              </Suspense>
+            ) : (
+              <SlabBoundaryEditor slabId={selectedSlabId} />
+            )
+          })()}
+        {showSlabHoleEditor &&
+          selectedSlabId &&
+          editingHole &&
+          (() => {
+            const Registry = getRegistryAffordanceTool('slab', 'hole-edit')
+            return Registry ? (
+              <Suspense fallback={null}>
+                <Registry holeIndex={editingHole.holeIndex} slabId={selectedSlabId} />
+              </Suspense>
+            ) : (
+              <SlabHoleEditor holeIndex={editingHole.holeIndex} slabId={selectedSlabId} />
+            )
+          })()}
         {showCeilingBoundaryEditor && selectedCeilingId && (
           <CeilingBoundaryEditor ceilingId={selectedCeilingId} />
         )}

packages/editor/src/index.tsx

@@ -14,6 +14,11 @@ export {
   snapFenceDraftPoint,
 } from './components/tools/fence/fence-drafting'
 export { CursorSphere } from './components/tools/shared/cursor-sphere'
+// Phase 5 Stage D — PolygonEditor for slab/ceiling boundary + hole editors.
+export {
+  PolygonEditor,
+  type PolygonEditorProps,
+} from './components/tools/shared/polygon-editor'
 export {
   formatAngleRadians,
   getAngleToSegmentReference,