Fix editor regressions and add Blender scene and animated material import

docs/VALIDATION.md

@@ -16,3 +16,15 @@ The local editor was opened in a desktop browser. Visual checks covered the init
 GitHub Actions repeats the clean install, build, type check and test suite on Node.js 22. The build runs before integration tests because they read the generated editor and player bundles.
 
 Native application binaries were not rebuilt for this engine-only package; the tests cover build packaging and orchestration, not real installation on every target device.
+
+## Blender import and regression validation — 2026-09-12
+
+- Build and TypeScript checks pass after the Blender import changes.
+- Added regression coverage for parent/child material isolation, nested hosted export URLs, draft namespaces, and shared first-person input handling.
+- Generated glTF fixtures exercise skeletal animation, morph targets, material color/alpha/metallic/roughness, perspective and orthographic camera properties, light intensity, autoplay, independent instances and disposal.
+- Import tests cover glTF resource ZIPs, missing files, traversal rejection, scene camera/lighting selection, and atomic MCP scene replacement with Undo.
+- An optional real Blender 5.2.1 LTS integration test creates a synthetic scene, bakes a procedural material animated by a `frame` driver, converts a curve, exports shape keys/camera/light, checks scene isolation, and verifies unchanged input bytes.
+- A local WebGL smoke test used a three-frame bake from an existing procedural material. All four atlas offsets changed together; pause held the frame fixed. The scene rendered in the browser. Personal project files and generated results remain outside Git.
+- The exported browser-only editor loaded and ran a generated animated Blender scene under a nested URL.
+
+Full Cycles/EEVEE equivalence, every Blender node type, full user-scene conversion and device-specific performance are not claimed. See [Blender compatibility](BLENDER.md).