fix(case): expose source audio in admin detail

frontend/src/api/aihr/case.ts

@@ -36,6 +36,8 @@ export type CaseDetailResponse = {
   owner: string;
   transcript: string;
   summary: string;
+  mediaUrl?: string;
+  mediaOssId?: number | null;
 };
 
 export type CaseUploadResponse = {

frontend/src/views/knowledge/cases.vue

@@ -135,6 +135,10 @@
           <strong>案例摘要</strong>
           <p>{{ caseDetail.summary || '暂无案例摘要' }}</p>
         </div>
+        <div v-if="caseDetail.mediaUrl" class="detail-block">
+          <strong>原始音频</strong>
+          <audio class="case-audio" :src="caseDetail.mediaUrl" controls preload="metadata" />
+        </div>
         <el-alert title="当前版本提供转写、摘要和状态详情；视频样片、学习点与主管点评待正式媒体和业务字段接入。" type="info" :closable="false" />
       </template>
       <el-empty v-else description="暂无详情" />
@@ -697,6 +701,12 @@ onMounted(() => {
   }
 }
 
+.case-audio {
+  display: block;
+  width: 100%;
+  margin-top: 10px;
+}
+
 .record-table {
   border: 1px solid #edf0f5;
   border-radius: 8px;