恢复普通媒体画布时长状态

非角色动作图层继续从画布布局恢复音频和视频运行时秒数。

账号素材转图层时保留前端临时媒体时长，不写入角色动作正式字段。

补充音频图层时长恢复回归测试。

src/components/image-editor/ImageCanvasEditorModel.test.ts

@@ -589,6 +589,7 @@ describe('ImageCanvasEditorModel', () => {
         sourceType: 'generated',
         mediaType: 'audio',
         assetKind: 'sound-effect',
+        durationSeconds: 3.5,
       },
       new Map([
         [
@@ -605,6 +606,7 @@ describe('ImageCanvasEditorModel', () => {
       src: '/generated-character-drafts/editor-audios/sfx.mp3',
       mediaType: 'audio',
       assetKind: 'sound-effect',
+      durationSeconds: 3.5,
     });
   });
 

src/components/image-editor/ImageCanvasEditorModel.ts

@@ -186,6 +186,7 @@ export function createLayerFromAsset(
     objectKey: asset.objectKey,
     assetObjectId: asset.assetObjectId,
     sourceResourceId: asset.sourceResourceId,
+    durationSeconds: asset.durationSeconds,
     sourceAssetId: asset.id,
     assetKind,
     generationInputs: asset.generationInputs,
@@ -781,6 +782,9 @@ export function hydrateLayer(
       ? stringOrNull(resource?.assetObjectId)
       : stringOrNull(snapshot.assetObjectId) ??
         stringOrNull(resource?.assetObjectId),
+    durationSeconds: isCharacterAnimation
+      ? undefined
+      : audioDurationOrNull(snapshot.durationSeconds),
     imageSequenceDurationMs: isCharacterAnimation
       ? audioDurationOrNull(resource?.imageSequenceDurationMs)
       : undefined,

src/components/image-editor/ImageCanvasEditorTypes.ts

@@ -60,6 +60,7 @@ export type EditorAsset = {
   showcaseSubmitError?: string | null;
   assetKind?: CanvasAssetKind | null;
   generationInputs?: CanvasGenerationInputs | null;
+  durationSeconds?: number;
   imageSequenceFrames?: EditorImageSequenceFrameResult[];
   imageSequenceDurationMs?: number;
   uploadStatus?: 'uploading' | 'failed';