feat(web): finish RE 5000PBR lesson video and fix non-ASCII GLB import

- Add 11:07 Chinese-narrated lesson video, VTT, poster and 13 chapter screenshots.
- Regenerate 20-render WebGL2 matrix and 15 operation captures on RTX 4060.
- Fix WASM staging for non-ASCII import filenames (猴头.glb); rebuild web_engine.
- Harden lesson video recording pipeline; fix stale lesson-link E2E selector.
- Add RE PBR derived libraries, lesson page, evidence and status report.

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

tools/web/generate-pbr-tutorial-renders.py

@@ -0,0 +1,130 @@
+"""Render the 12 tutorial material/model combinations with desktop Blender.
+
+Usage:
+  build_blender_native/bin/blender --background --factory-startup \
+    --python tools/web/generate-pbr-tutorial-renders.py -- \
+    web/app/public/tutorial/pbr/studio.blend \
+    web/app/public/assets/pbr-library/pbr-library.blend \
+    web/app/public/tutorial/pbr/renders
+"""
+
+import hashlib
+import json
+import pathlib
+import sys
+
+import bpy
+
+
+MODELS = [
+    ("PBR Suzanne", "suzanne"),
+    ("PBR Cube", "cube"),
+    ("PBR Torus", "torus"),
+]
+MATERIALS = [
+    ("PBR Metal Brushed", "metal-brushed"),
+    ("PBR Glass", "glass"),
+    ("PBR Wood", "wood"),
+    ("PBR Emission Cyan", "emission-cyan"),
+]
+
+
+def sha256_file(path):
+    digest = hashlib.sha256()
+    with path.open("rb") as handle:
+        for chunk in iter(lambda: handle.read(1024 * 1024), b""):
+            digest.update(chunk)
+    return digest.hexdigest()
+
+
+def append_library(blend_path):
+    with bpy.data.libraries.load(str(blend_path), link=False) as (data_from, data_to):
+        data_to.objects = list(data_from.objects)
+        data_to.materials = list(data_from.materials)
+        data_to.images = list(data_from.images)
+    return data_to.objects, data_to.materials
+
+
+def main(studio_path, library_path, renders_dir):
+    studio = pathlib.Path(studio_path).resolve()
+    library = pathlib.Path(library_path).resolve()
+    out = pathlib.Path(renders_dir).resolve()
+    out.mkdir(parents=True, exist_ok=True)
+
+    bpy.ops.wm.open_mainfile(filepath=str(studio))
+    scene = bpy.context.scene
+    objects, materials = append_library(library)
+    material_by_name = {material.name: material for material in materials if material}
+    model_by_name = {}
+    for obj in objects:
+        if obj is None:
+            continue
+        scene.collection.objects.link(obj)
+        model_by_name[obj.name] = obj
+        obj.hide_render = True
+
+    scene.render.engine = "BLENDER_EEVEE"
+    scene.render.resolution_x = 1024
+    scene.render.resolution_y = 1024
+    scene.render.resolution_percentage = 100
+    scene.render.image_settings.file_format = "PNG"
+    scene.render.image_settings.color_mode = "RGBA"
+    scene.render.image_settings.color_depth = "8"
+    scene.render.film_transparent = False
+    scene.render.dither_intensity = 0
+    scene.eevee.taa_render_samples = 64
+    scene.view_settings.look = "None"
+
+    manifest = []
+    for model_name, model_slug in MODELS:
+        model = model_by_name[model_name]
+        for material_name, material_slug in MATERIALS:
+            for other in model_by_name.values():
+                other.hide_render = other is not model
+            material = material_by_name.get(material_name)
+            if material is None:
+                raise RuntimeError(f"missing material {material_name}")
+            model.data.materials.clear()
+            model.data.materials.append(material)
+            png = out / f"{model_slug}-{material_slug}.png"
+            jpg = out / f"{model_slug}-{material_slug}.jpg"
+            scene.render.filepath = str(png)
+            bpy.ops.render.render(write_still=True)
+            scene.render.image_settings.file_format = "JPEG"
+            scene.render.image_settings.color_mode = "RGB"
+            scene.render.image_settings.quality = 90
+            scene.render.filepath = str(jpg)
+            bpy.ops.render.render(write_still=True)
+            scene.render.image_settings.file_format = "PNG"
+            scene.render.image_settings.color_mode = "RGBA"
+            manifest.append({
+                "model": model_name,
+                "modelSlug": model_slug,
+                "material": material_name,
+                "materialSlug": material_slug,
+                "png": str(png.relative_to(pathlib.Path(__file__).resolve().parents[2])).replace("\\", "/"),
+                "jpg": str(jpg.relative_to(pathlib.Path(__file__).resolve().parents[2])).replace("\\", "/"),
+                "width": 1024,
+                "height": 1024,
+                "bytes": png.stat().st_size,
+                "sha256": sha256_file(png),
+            })
+
+    (out / "manifest.json").write_text(
+        json.dumps({
+            "schemaVersion": 1,
+            "renderer": "DESKTOP_BLENDER_EEVEE",
+            "blenderVersion": ".".join(str(value) for value in bpy.app.version),
+            "renders": manifest,
+        }, indent=2, ensure_ascii=True) + "\n",
+        encoding="utf-8",
+        newline="\n",
+    )
+    print(json.dumps({"renders": len(manifest), "output": str(out)}))
+
+
+if __name__ == "__main__":
+    arguments = sys.argv[sys.argv.index("--") + 1:] if "--" in sys.argv else []
+    if len(arguments) != 3:
+        raise SystemExit("usage: blender --background --factory-startup --python generate-pbr-tutorial-renders.py -- STUDIO LIBRARY RENDERS")
+    main(*arguments)