Android Offline Maps Manager
class AndroidOfflineMapsManager(appContext: Context, soundscapeServiceConnection: SoundscapeServiceConnection)
Session-scope facade over the offline-map manifest fetcher, file system index, and OfflineDownloader. Implements the surface area the shared NavGraph expects on iOS via OfflineMapManager: full list of manifest extracts, downloaded extracts as a FeatureCollection, current download state, and refresh / containing-query / start / cancel / delete operations.