chore: checkpoint web Blender migration source, tools and docs

Accumulated uncommitted work: GHOST Web backend, WebGL/GPU web layer,
web workflow engine and protocol, tooling, docs and task records.
Large generated evidence, user-testing archives, build snapshots and
imported test assets remain untracked.

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

web/tests/unit/glb-negative-cases.test.mjs

@@ -50,6 +50,14 @@ test("M12-06F rejects sparse accessors, extensions and external URIs", () => {
   assert.throws(() => protocol.importGLBSemantics(arrayBuffer(rewriteJson((document) => { document.buffers[0].uri = "external.bin"; }))), /GLB_EXTERNAL_URI_BLOCKED/);
 });
 
+test("M12-06F accepts the bounded material extensions emitted by the exporter", () => {
+  const imported = protocol.importGLBSemantics(arrayBuffer(rewriteJson((document) => {
+    document.extensionsUsed = ["KHR_materials_ior", "KHR_materials_emissive_strength"];
+  })));
+  assert.equal(imported.version, 2);
+  assert.deepEqual(imported.meshes.map((mesh) => mesh.name), ["M12 Mesh Fixture Mesh"]);
+});
+
 test("M12-06F rejects over-budget GLB bytes and table counts", () => {
   const oversized = Buffer.alloc(protocol.GLB_IMPORT_BUDGET.maxBytes + 1);
   source.copy(oversized);