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>

web/protocol/asset-catalog-v2.ts

@@ -472,3 +472,52 @@ export async function createAssetCatalogManifestV2FromDesktop(value: unknown, re
   const manifest = { schemaVersion: ASSET_CATALOG_SCHEMA, revision, catalogs, assets, libraries: [] };
   return parseAssetCatalogManifestV2(manifest);
 }
+
+export interface AssetCatalogMergeResult {
+  manifest: AssetCatalogManifestV2IR;
+  conflicts: string[];
+  added: { catalogs: number; assets: number; libraries: number };
+}
+
+/** Merge an independently generated library into the existing global catalog. */
+export async function mergeAssetCatalogManifests(existingValue: unknown, incomingValue: unknown): Promise<AssetCatalogMergeResult> {
+  const existing = await parseAssetCatalogManifestV2(existingValue);
+  const incoming = await parseAssetCatalogManifestV2(incomingValue);
+  const conflicts: string[] = [];
+  const mergeList = <T>(base: readonly T[], extra: readonly T[], key: (value: T) => string, label: string): T[] => {
+    const merged = new Map(base.map((value) => [key(value), value]));
+    for (const value of extra) {
+      const id = key(value);
+      const current = merged.get(id);
+      if (!current) {
+        merged.set(id, structuredClone(value) as T);
+      } else if (JSON.stringify(current) !== JSON.stringify(value)) {
+        conflicts.push(`${label}:${id}`);
+      }
+    }
+    return [...merged.values()];
+  };
+  const catalogs = mergeList(existing.catalogs, incoming.catalogs, (value) => value.catalogId, "catalog");
+  const assets = mergeList(existing.assets, incoming.assets, (value) => value.assetId, "asset");
+  const libraries = mergeList(existing.libraries, incoming.libraries, (value) => value.libraryId, "library");
+  const revision = Math.max(existing.revision, incoming.revision) + 1;
+  if (revision > Number.MAX_SAFE_INTEGER) {
+    throw new AssetCatalogV2ValidationError("ASSET_BUDGET_EXCEEDED", "asset catalog revision overflow");
+  }
+  const manifest = await parseAssetCatalogManifestV2({
+    schemaVersion: ASSET_CATALOG_SCHEMA,
+    revision,
+    catalogs,
+    assets,
+    libraries,
+  });
+  return {
+    manifest,
+    conflicts,
+    added: {
+      catalogs: catalogs.length - existing.catalogs.length,
+      assets: assets.length - existing.assets.length,
+      libraries: libraries.length - existing.libraries.length,
+    },
+  };
+}