editor: tool-defaults seeding + drawTool capability (fence presets) (#346)

* feat(editor): tool-defaults seeding + drawTool capability; fence consumes it

Adds a generic, transient `useEditor.toolDefaults` slice keyed by tool, set
via `setToolDefaults(tool, params)`. A draw tool's create path merges its
entry when minting a node and clears it on deactivation, so a host app can
prime the next-drawn node's parameters — placing a saved preset of a drawn
kind, or a future "small / medium / large" dimension picker for
wall / slab / ceiling.

Marks the kind with `capabilities.drawTool` (helper `isDrawnViaTool`) so host
apps know to route placement through `setToolDefaults(type) + setTool(type)`
instead of cloning a finished instance.

Wires fence end-to-end: it declares `drawTool: true`, its create path merges
`toolDefaults.fence`, and the draft preview (bar geometry, cursor, HUD label
heights) reflects the seeded height/thickness so the ghost matches what will
be built. The tool clears its own defaults on unmount.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

* fix(editor): restore dropped useEditor import in fence tool

The toolDefaults-seeding commit lost the `useEditor` import (formatter
stripped it), shipping a runtime ReferenceError when FenceTool mounts.
Re-add it.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.7 <noreply@anthropic.com>

packages/nodes/src/fence/definition.ts

@@ -1,8 +1,4 @@
-import {
-  type FenceNode as FenceNodeType,
-  type HandleDescriptor,
-  type NodeDefinition,
-} from '@pascal-app/core'
+import type { FenceNode as FenceNodeType, HandleDescriptor, NodeDefinition } from '@pascal-app/core'
 import { buildFenceFloorplan } from './floorplan'
 import { fenceCurveAffordance, fenceMoveEndpointAffordance } from './floorplan-affordances'
 import { fenceFloorplanMoveTarget } from './floorplan-move'
@@ -164,6 +160,10 @@ export const fenceDefinition: NodeDefinition<typeof FenceNode> = {
     surfaces: { sides: { faces: 'all' } },
     duplicable: true,
     deletable: true,
+    // Placed by drawing the span with the two-click tool; a saved preset
+    // seeds its build parameters via `toolDefaults.fence` (see `tool.tsx`
+    // and `createFenceOnCurrentLevel`).
+    drawTool: true,
   },
 
   relations: {