修复 SGS SDK 导览数据源与模型加载

升级 SDK API 数据契约，补齐 guideStops、业务 POI、诊断与路线数据接口。

修复 SDK 模式下 POI/模型/楼层混用静态数据的问题，并为 ThreeMap 模型加载增加短退避重试。

src/repositories/GuideRepository.ts

@@ -255,7 +255,6 @@ export class SgsSdkGuideRepository implements GuideRepository {
   private floorsCache: MuseumFloor[] | null = null
   private poiCache: MuseumPoi[] | null = null
   private floorAliases: Map<string, string> | null = null
-  private readonly staticFallback = new StaticGuideRepository()
 
   constructor(private readonly provider: SgsSdkApiProvider = defaultSgsSdkApiProvider) {}
 
@@ -331,7 +330,7 @@ export class SgsSdkGuideRepository implements GuideRepository {
     const pois = await this.listPois()
     return pois.find((poi) => poi.id === id)
       || findPoiByNavIdNameFallback(pois, id)
-      || this.staticFallback.getPoiById(id)
+      || null
   }
 
   async searchPois(keyword = '') {