Phase 5 Stage D fence: port MoveFenceEndpointTool to DragAction

Second Stage D affordance port (425 LoC legacy → ~430 split across
action + wrapper). All math (snap, linked-fence cascade, alt-detach,
min-length gate, single-undo dance) lives in the pure
`moveFenceEndpointDragAction`. The React wrapper handles the UI
overlays (cursor sphere, Drag/Detach badge, angle label) and the live
state subscriptions.

The action introduces the single-undo dance pattern for multi-write
commits: `commit()` calls `scene.restoreAll()` → `resumeHistory()` →
re-applies the final draft so zundo records the entire drag as one
undo step. Reusable shape for slab/wall/door endpoint ports.

Transitional exports added to `@pascal-app/editor`'s public surface
(`snapFenceDraftPoint`, `isWallLongEnough`, the segment-angle helpers,
`MovingFenceEndpoint`). Stage F cleanup moves these into
`@pascal-app/nodes` once every consumer is registry-driven.

`getRegistryAffordanceTool` is now generic (`ComponentType<any>`) so
affordances with different prop shapes (`{ node }`, `{ target }`, …)
all dispatch through the same helper.

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

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

@@ -58,18 +58,15 @@ function getRegistryTool(tool: Tool | null): ComponentType | null {
  * Returns null when the kind doesn't declare the affordance — caller
  * renders the legacy fallback in that case.
  */
-function getRegistryAffordanceTool(
-  kind: string,
-  affordance: string,
-): ComponentType<{ node: any }> | null {
+function getRegistryAffordanceTool(kind: string, affordance: string): ComponentType<any> | null {
   const def = nodeRegistry.get(kind)
   const loader = def?.affordanceTools?.[affordance]
   if (!loader) return null
   const cached = lazyToolCache.get(loader)
-  if (cached) return cached as ComponentType<{ node: any }>
-  const Comp = lazy(loader as () => Promise<{ default: ComponentType<{ node: any }> }>)
+  if (cached) return cached
+  const Comp = lazy(loader as () => Promise<{ default: ComponentType<any> }>)
   lazyToolCache.set(loader, Comp as unknown as ComponentType)
-  return Comp
+  return Comp as unknown as ComponentType<any>
 }
 
 const tools: Record<Phase, Partial<Record<Tool, React.FC>>> = {
@@ -212,7 +209,20 @@ export const ToolManager: React.FC = () => {
           <CeilingHoleEditor ceilingId={selectedCeilingId} holeIndex={editingHole.holeIndex} />
         )}
         {movingWallEndpoint && <MoveWallEndpointTool target={movingWallEndpoint} />}
-        {movingFenceEndpoint && <MoveFenceEndpointTool target={movingFenceEndpoint} />}
+        {movingFenceEndpoint &&
+          (() => {
+            const RegistryAffordance = getRegistryAffordanceTool(
+              movingFenceEndpoint.fence.type,
+              'move-endpoint',
+            )
+            return RegistryAffordance ? (
+              <Suspense fallback={null}>
+                <RegistryAffordance target={movingFenceEndpoint} />
+              </Suspense>
+            ) : (
+              <MoveFenceEndpointTool target={movingFenceEndpoint} />
+            )
+          })()}
         {curvingWall && <CurveWallTool node={curvingWall} />}
         {curvingFence &&
           (() => {

packages/editor/src/index.tsx

@@ -4,7 +4,18 @@ export {
   type SnapshotCameraData,
   ThumbnailGenerator,
 } from './components/editor/thumbnail-generator'
+// Phase 5 Stage D transitional exports — pure drafting / angle helpers
+// consumed by kind-owned drag actions in @pascal-app/nodes. Stage F
+// cleanup moves these into @pascal-app/nodes (fence/drafting.ts +
+// shared/segment-angle.ts) once every Stage D port is in.
+export { type FencePlanPoint, snapFenceDraftPoint } from './components/tools/fence/fence-drafting'
 export { CursorSphere } from './components/tools/shared/cursor-sphere'
+export {
+  formatAngleRadians,
+  getAngleToSegmentReference,
+  getSegmentAngleReferenceAtPoint,
+} from './components/tools/shared/segment-angle'
+export { isWallLongEnough } 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'
@@ -36,7 +47,12 @@ export { applySceneGraphToEditor } from './lib/scene'
 export { triggerSFX } from './lib/sfx-bus'
 export { default as useAudio } from './store/use-audio'
 export { type CommandAction, useCommandRegistry } from './store/use-command-registry'
-export type { FloorplanSelectionTool, SplitOrientation, ViewMode } from './store/use-editor'
+export type {
+  FloorplanSelectionTool,
+  MovingFenceEndpoint,
+  SplitOrientation,
+  ViewMode,
+} from './store/use-editor'
 export { default as useEditor } from './store/use-editor'
 export {
   type PaletteView,