修正AI助学未保存提示

src/views/components/TrainingAiSidebar.vue

@@ -140,6 +140,10 @@ async function requestAssist() {
     assistMessage.value = "请输入问题，或点击上方参考提示词后发送。";
     return;
   }
+  if (currentTaskKey.value && !props.hasSavedAnswer) {
+    assistMessage.value = "请先至少填写并保存一项实训内容，再请求 AI 助学。";
+    return;
+  }
   assistMessages.value.push({ id: `student-${Date.now()}`, role: "student", content: question });
   assistQuestion.value = "";
   if (currentTaskKey.value) {