修复讲解全局音频播放器交互

src/usecases/explainUseCase.ts

@@ -191,7 +191,8 @@ export class ExplainUseCase {
     fallback?: MuseumExhibit | null
   ): MuseumExhibit {
     const linkedPrimary = stopInfo.linkedExhibits[0]
-    const coverImage = stopInfo.coverImageUrl || (stopInfo.imageStatus === 'READY' ? fallback?.image : undefined)
+    const linkedCoverImage = stopInfo.linkedExhibits.find((item) => item.coverImageUrl)?.coverImageUrl
+    const coverImage = stopInfo.coverImageUrl || linkedCoverImage || fallback?.image
     const description = stopInfo.description || fallback?.description || '该讲解暂无简介。'
     const audioTarget = this.resolveStopInfoAudioTarget(stopInfo)
     const audioAvailable = stopInfo.audioStatus === 'READY'