regenerate something when the sentences changed

ios/OralTrainer/Views/PlayerSectionView.swift

@@ -27,7 +27,8 @@ struct PlayerSectionView: View {
             SentenceExplanationSheet(
                 mediaId: controller.currentItem?.id ?? "",
                 courseTitle: controller.currentItem?.title ?? "口语训练课程",
-                sentence: sentence
+                sentence: sentence,
+                sentences: controller.currentItem?.sentences ?? []
             )
         }
     }
@@ -273,6 +274,7 @@ struct SentenceExplanationSheet: View {
     let mediaId: String
     let courseTitle: String
     let sentence: SentenceBoundary
+    var sentences: [SentenceBoundary] = []
 
     @Environment(\.dismiss) private var dismiss
     @State private var explanation = ""
@@ -327,6 +329,7 @@ struct SentenceExplanationSheet: View {
             }
         }
         .task {
+            SentenceExplanationStore.shared.sync(mediaId: mediaId, sentences: sentences)
             if let cached = SentenceExplanationStore.shared.load(
                 mediaId: mediaId,
                 sentenceIndex: sentence.index