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/protocol/workbench-command-groups.ts

@@ -1,11 +1,11 @@
 import { getWebEngineCommandCapability, type WebEngineCommandType } from "./web-engine-capabilities";
 
 export const WORKBENCH_COMMAND_GROUPS = Object.freeze({
-  OBJECT: ["createPrimitive", "duplicateObject", "deleteObject", "setObjectTransform", "setParent", "createCollection", "moveObjectToCollection", "renameId", "applyObjectTransform", "setObjectOrigin"],
+  OBJECT: ["createPrimitive", "duplicateObject", "deleteObject", "setObjectTransform", "setParent", "createCollection", "moveObjectToCollection", "renameId", "applyObjectTransform", "setObjectOrigin", "assignMaterialSlot"],
   MESH: ["meshEdit", "translateMeshVertices", "createUVMap", "setActiveUVMap", "unwrapUV", "setVertexColors", "setVertexWeights"],
   ANIMATION: ["setFrame", "insertObjectKeyframe", "deleteObjectKeyframe", "setFCurveInterpolation", "setConstraint", "setNLAStack", "setNLAProperty"],
   RENDER: ["setCameraProperties", "setLightProperties", "setWorldProperties", "setSceneProperties", "setSceneRenderSettings", "setSceneAudioSettings", "setSceneUnitSettings", "setSceneTimelineSettings", "setScenePipelineSettings", "setSceneBindings", "setSceneViewLayerSettings", "setSceneCollectionSettings", "setSceneBorderSettings", "setSceneSimplifySettings", "setSceneColorManagement", "setSceneImageFormat", "setSceneMotionBlur", "setSceneHairSettings", "setSceneCompositorSettings", "setScenePerformanceSettings", "setSceneSamplingSettings", "setSceneMultiviewSettings", "setSceneStampSettings", "setSceneLineSettings", "setSceneViewLayerPassSettings", "setSceneViewLayerAOVs", "setSceneViewLayerLightgroups", "setObjectLightgroup", "setWorldLightgroup"],
-  IO: ["importImage", "importVFont", "setMaterialImageNode"],
+  IO: ["importImage", "packImage", "importVFont", "setMaterialImageNode"],
 } as const satisfies Record<string, readonly WebEngineCommandType[]>);
 
 export function isWorkbenchCommandAvailable(type: unknown): type is WebEngineCommandType {