Fix stale packed textures in summit marker export

tests/summit-marker.test.ts

@@ -1,8 +1,24 @@
 import assert from 'node:assert/strict';
 import test from 'node:test';
+import { readFileSync } from 'node:fs';
 import { BoxGeometry, Group, Mesh, MeshStandardMaterial, Vector3 } from 'three';
 import { createSummitMarker } from '../src/scene/summitMarker.ts';
 
+test('exported marker embeds the current baked textures, not stale packed images', () => {
+  const glb = readFileSync(new URL('../public/models/summit/summit-marker.glb', import.meta.url));
+  const jsonLength = glb.readUInt32LE(12);
+  const document = JSON.parse(glb.subarray(20, 20 + jsonLength).toString());
+  const binaryStart = 28 + jsonLength;
+  assert.equal(document.images.length, 4);
+  for (const image of document.images) {
+    const view = document.bufferViews[image.bufferView];
+    const start = binaryStart + (view.byteOffset ?? 0);
+    const embedded = glb.subarray(start, start + view.byteLength);
+    const source = readFileSync(new URL(`../public/terrain/materials/${image.name}.png`, import.meta.url));
+    assert.ok(embedded.equals(source), `${image.name} must match the latest bake`);
+  }
+});
+
 test('marker seats its foot on sloping bedrock without deforming the stone', () => {
   const asset = new Group();
   const mesh = new Mesh(new BoxGeometry(4, 4, 2), new MeshStandardMaterial());