perf(canvas): 画布媒体 - 优化媒体加载、播放器与节点交互 (#357)

Merge origin/main at fb089b2 and retain canvas media performance, player layout, and interaction updates.

Co-authored-by: ddCat <2695092045@qq.com>

web/src/services/project-asset-sync.ts

@@ -1,4 +1,5 @@
 import { canvasNodeToAsset, declaredCanvasNodeAssetCategory, findCanvasNodeAsset, type CanvasAssetSource } from "@/lib/canvas/canvas-node-asset";
+import { canvasVideoAssetPreviewUrl } from "@/lib/canvas/canvas-media-preview";
 import { readImageMeta } from "@/lib/image-utils";
 import { parseBackendGenerationResult, type BackendGenerationResult } from "@/services/api/generation-task";
 import { linkProjectAsset, moveProjectAsset, updateProjectAssetCategory } from "@/services/api/projects";
@@ -284,7 +285,7 @@ async function generationOutputAsset(input: Parameters<MaterializeGenerationTask
         return {
             kind: "video",
             title: "生成视频",
-            coverUrl: stored.url,
+            coverUrl: canvasVideoAssetPreviewUrl(stored.url),
             tags: ["生成"],
             status: "confirmed",
             source: "生成任务",