Add a node that names the render layer of an object (#305)

The issue asked for Set render layer, Set sees and Render layer of. As
with #211, a probe showed that writing already works. A Properties
node of the object's type writes Render layer during a run, Inherit
included, and one of type Camera writes Sees. The next picture follows
both. As agreed, only Render layer of is built, and writing stays with
Properties.

- Render layer of is a data node with the input object and the outputs
  name and number. It answers the layer that holds, so an object
  without a choice of its own names its parent's.
- NodeContext.renderLayerOf answers the number with the same rule the
  drawing uses (renderLayerAlong). The new field renderLayers on
  GraphLookup brings the names to the node.
- hasRenderLayer in PropertySchema says which types are drawn.
- Decided here: for an object that is not drawn (a camera, a
  behavior, a collider) the name is empty and the number -1, as Layer
  of does without a collider.

Changing the render layer or Sees during a run had no test so far.
Three unit tests now hold the proof from the issue.

Tests:
- Gate: 231 files, 3534 tests (3526 + 8), exit 0
- e2e 6: 149 checks passed, e2e 63: 13 checks passed (+1)
- Unit: the coin moves into the overlay with Set and back with
  Inherit, a HUD container takes its sprite along, the main camera sees
  a second layer once its Sees is set, and Render layer of names the
  inherited layer, and none for a behavior
- Node catalog: four cases for Render layer of
- 63c3 moves a sprite onto UI in a Play run: the main camera no longer
  draws it, and the log reads "UI" and "1"
- Three counter-probes fail 1, 1 and 2 tests: without inheriting in
  the node, without the check for a drawn type, and without
  inheriting in the drawing
- "layer of" in the palette still finds Layer of first (6z-x)
- The e2e sum is 1731 (1730 plus 1)

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

tools/e2e/63-render-layers.mjs

@@ -4,7 +4,8 @@
  * a green sprite of the overlay with z -10 covers a red one of the main camera with z 1000, and
  * what a camera does not see stays away – a yellow `UI` sprite in front of the main camera, a blue
  * `Default` one in front of the overlay. Switched to no overlay, the second camera draws nothing.
- * `Is hovered` and `Mouse position` find the mouse through the overlay camera too (#304).
+ * `Is hovered` and `Mouse position` find the mouse through the overlay camera too (#304), and a
+ * graph moves a sprite onto another layer while the game runs (#305).
  * Then the main camera wears a shader over its picture (#299), in the Game tab and, switched on in
  * the eye, in the scene view.
  *
@@ -187,6 +188,54 @@ export async function renderLayers(t) {
     JSON.stringify({ hovered, overlayX }),
   );
 
+  // 63c3. (#305) A graph moves the red square A onto `UI` with a Properties node once the game runs:
+  //       the main camera no longer draws it, and `Render layer of` names its new layer.
+  const switchGraph = {
+    nodes: [
+      node('rl63-start', 'OnStart', 0),
+      node('rl63-a-find', 'ObjectByName', 0, { name: 'A 63' }),
+      {
+        ...node('rl63-set', 'Properties', 200, { objectType: 'sprite', renderLayer: 1 }),
+        ports: [{ key: 'renderLayer', kind: 'number', write: true }],
+      },
+      node('rl63-of', 'RenderLayerOf', 200),
+      node('rl63-name', 'Log', 400),
+      node('rl63-number', 'Log', 600),
+    ],
+    edges: [
+      edge('rl63-s1', 'rl63-start', 'exec', 'rl63-set', 'exec'),
+      edge('rl63-s2', 'rl63-set', 'exec', 'rl63-name', 'exec'),
+      edge('rl63-s3', 'rl63-name', 'exec', 'rl63-number', 'exec'),
+      edge('rl63-s4', 'rl63-a-find', 'object', 'rl63-set', 'object'),
+      edge('rl63-s5', 'rl63-a-find', 'object', 'rl63-of', 'object'),
+      edge('rl63-s6', 'rl63-of', 'name', 'rl63-name', 'message'),
+      edge('rl63-s7', 'rl63-of', 'number', 'rl63-number', 'message'),
+    ],
+  };
+  await mutate(`
+    const p = __gm.state.project;
+    const scene = __gm.state.activeScene;
+    p.assets.push({ id: 'rl63-switch', type: 'behavior', name: 'Switch 63', props: { enabled: true, runInEditor: false }, variables: [], graph: ${JSON.stringify(switchGraph)} });
+    ${MAKE_OBJECT}
+    scene.objects.push(make('rl63-switcher', 'rl63-switch', '', 0, 'Switch 63'));
+  `);
+  await play();
+  await sleep(400);
+  const switched = await picture();
+  const named = (await json('__gm.world()'))?.log.slice(-2) ?? [];
+  await stop();
+  await mutate(`
+    const p = __gm.state.project;
+    const scene = __gm.state.activeScene;
+    scene.objects = scene.objects.filter((o) => o.id !== 'rl63-switcher');
+    p.assets = p.assets.filter((a) => a.id !== 'rl63-switch');
+  `);
+  check(
+    'a graph moves a sprite onto UI while the game runs, and Render layer of names it',
+    !switched.main.includes('rl63-a') && !is(switched.right, RED) && JSON.stringify(named) === '["UI","1"]',
+    JSON.stringify({ switched, named }),
+  );
+
   // 63d. The project settings list the render layers, apart from the collision layers.
   await t.clickToolbar('menu');
   await clickText('Project settings…');