Add a Get world position node with just the world x and y

Get position hands out four numbers, local and world. A graph that
only needs where an object is in the world had to pick the two world
ports out of four and leave the local ones dangling.

- Get world position has one object input and the outputs x and y.
  It reads the same worldPositionOf as Get position, so a child adds
  every parent's position in.
- Without an object it reports the origin, like Get position.

Tests:
- Node catalog: a top-level object, a child under a parent and no
  object (3 cases).
- node-catalog and hierarchy: 2 files, 378 tests, all green. The
  full gate was not run for this commit, CI covers it.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/core/graph/nodes/data/GetWorldPosition.ts

@@ -0,0 +1,19 @@
+import { worldPositionOf } from '../../NodeContext';
+import type { NodeDef } from '../../NodeRegistry';
+import { asEntity } from '../../values';
+import { num, obj } from '../shared';
+
+export const GetWorldPosition: NodeDef = {
+  type: 'GetWorldPosition',
+  label: 'Get world position',
+  category: 'data',
+  description: 'The position of an object in world units, with every parent added in.',
+  inputs: [obj('object')],
+  outputs: [num('x'), num('y')],
+  params: [],
+  run: (_ctx, inputs) => {
+    const target = asEntity(inputs.object);
+    const world = target ? worldPositionOf(target) : { x: 0, y: 0 };
+    return { outputs: { x: world.x, y: world.y } };
+  },
+};

src/core/graph/nodes/index.ts

@@ -44,6 +44,7 @@ import { FindText } from './data/FindText';
 import { FirstNotEmpty } from './data/FirstNotEmpty';
 import { Floor } from './data/Floor';
 import { GetPosition } from './data/GetPosition';
+import { GetWorldPosition } from './data/GetWorldPosition';
 import { GetZ } from './data/GetZ';
 import { ChildByName } from './data/ChildByName';
 import { Children } from './data/Children';
@@ -201,6 +202,7 @@ export const BUILT_IN_NODES: readonly NodeDef[] = [
   IsEnabled,
   Properties,
   GetPosition,
+  GetWorldPosition,
   GetZ,
   TextureSize,
   AnimationPlaying,

tests/core/node-catalog.test.ts

@@ -752,6 +752,19 @@ const CASES: Record<string, Case[]> = {
       outputs: { x: 0, y: 0, worldX: 0, worldY: 0 },
     },
   ],
+  GetWorldPosition: [
+    {
+      name: 'a top-level object is at its own position',
+      inputs: { object: at('A', 10, 20) },
+      outputs: { x: 10, y: 20 },
+    },
+    {
+      name: 'a child is at the summed position of its parents',
+      inputs: { object: { ...at('child', 10, 20), parent: at('parent', 100, 200) } },
+      outputs: { x: 110, y: 220 },
+    },
+    { name: 'no object is the origin', inputs: { object: null }, outputs: { x: 0, y: 0 } },
+  ],
   GetZ: [
     {
       name: 'a child reports its own z and the z summed up with its parents',