接入编号讲解后端查询

- 使用真实讲解编号解析接口替换本地演示映射
- 成功后复用现有详情页并自动播放讲解
- 增加查询状态、业务错误提示和相关测试

Made-with: Proma

tests/unit/ExplainUseCase.spec.ts

@@ -33,11 +33,28 @@ const createUseCase = (detail: GuideStopDetail) => {
     getExhibitById: vi.fn().mockResolvedValue(null),
     listExplainExhibits: vi.fn().mockResolvedValue([])
   } as unknown as ExplainRepository
-  const audio = { getStopDetail: vi.fn().mockResolvedValue(detail) } as unknown as AudioPlayInfoRepository
+  const audio = {
+    getStopDetail: vi.fn().mockResolvedValue(detail),
+    getStopInfoByCode: vi.fn().mockResolvedValue({
+      available: true,
+      resolvedStopId: 'resolved-stop-1',
+      playTargetId: 'resolved-stop-1',
+      targetId: 'resolved-stop-1'
+    })
+  } as unknown as AudioPlayInfoRepository
   return { useCase: new ExplainUseCase(explain, audio), explain, audio }
 }
 
 describe('ExplainUseCase unified stop detail', () => {
+  it('resolves the museum code to the backend stop ID', async () => {
+    const { useCase, audio } = createUseCase(createDetail())
+
+    const result = await useCase.resolveExplainCode('1001', 'zh-CN')
+
+    expect(audio.getStopInfoByCode).toHaveBeenCalledWith('1001', 'zh-CN')
+    expect(result).toEqual({ code: '1001', stopId: 'resolved-stop-1' })
+  })
+
   it('uses stopId once in remote mode without requesting a catalog fallback', async () => {
     const originalMode = dataSourceConfig.explainContentMode
     Object.assign(dataSourceConfig, { explainContentMode: 'remote' })