feat(canvas): 画布工作台 - 新增生成副本并修复大型画布性能、素材同步与删除校验

统一图片与视频副本的生成落点并保留参考连接。\n优化大型画布节点虚拟化、媒体懒加载、拖拽与详情进入路径。\n修复素材主版本 ID 同步及删除时的画布独立引用校验。

web/src/services/user-data-sync.ts

@@ -2,6 +2,7 @@ import { getMediaBlob } from "@/services/file-storage";
 import { getImageBlob } from "@/services/image-storage";
 import { deleteRemoteAsset, deleteRemoteCanvasProject, getRemoteUserDataSnapshot, upsertRemoteAsset, upsertRemoteCanvasProject } from "@/services/api/user-data";
 import { resourceFileUrl, resourceIdFromStorageKey, resourceStorageKey, uploadResourceFile } from "@/services/api/resources";
+import { assetForRemoteSync } from "@/lib/asset-remote-sync";
 import type { Asset } from "@/stores/use-asset-store";
 import { flushAssetStorePersistence, useAssetStore } from "@/stores/use-asset-store";
 import type { CanvasProject } from "@/stores/canvas/use-canvas-store";
@@ -184,7 +185,7 @@ async function saveRemoteUserDataBatch() {
         acknowledgedProjects.set(source.id, source);
     }
     for (const source of dirtyAssets) {
-        const remotePayload = await ensureRemoteResourceReferences(source, uploaded);
+        const remotePayload = await ensureRemoteResourceReferences(assetForRemoteSync(source), uploaded);
         await upsertRemoteAsset(remotePayload);
         acknowledgedAssets.set(source.id, source);
     }