chore: checkpoint web Blender feature-gap work, docs and tests

- update native web_engine sources and rebuilt wasm artifacts
- add task cards, status notes and tooling scripts
- add web e2e specs, tutorial UI sources and tutorial assets
- sync golden task manifests and audit records

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

web/tests/e2e/smoke.spec.ts

@@ -1927,7 +1927,7 @@ test("renders local UV/color/material-slot geometry", async ({ page }) => {
   const canvas = page.locator("canvas.viewport-canvas");
   await expect(canvas).toHaveAttribute("data-renderer-backend", "webgl-pbr");
   await expect(canvas).toHaveAttribute("data-pbr-profile", "physical-v1");
-  await expect(canvas).toHaveAttribute("data-tone-mapping", "aces");
+  await expect(canvas).toHaveAttribute("data-tone-mapping", "agx");
   await expect(canvas).toHaveAttribute("data-shadow-map", "pcf-1024");
   const renderedPixels = await canvas.evaluate((canvas) => {
     const gl = canvas.getContext("webgl2") ?? canvas.getContext("webgl");